Checking the sLastErrorMsg property is always a good idea!

Luckily, if you are using the DispatchObject object wrapper that Sage provided, it includes a property indexer that makes it easy to do:
var lastError = poObject["sLastErrorMsg"];

That said, I got your code to work in my test project pretty much as is...
I fixed the nSetKey line to pass the string poNumber, vs. the object array named poPass.
The other thing I changed was the usage of InvokeMethodByRef to InvokeMethod, in a few places, where parameters are passed by value, not by ref.
Not sure if this caused any problem, but ByRef is more overhead so I only use it when needed.
Also I changed the vendor to 01-AIRWAY and the item code to "6655" to work with my ABX company, but everything else should fly.

Thanks!
Bret.

string poNumber = "";
//int test1 = (int)poObject.InvokeMethod("nGetNextPurchaseOrderNo");
object[] poPass = new object[] { poNumber };
successCheck((int)poObject.InvokeMethodByRef("nGetNextPurchaseOrderNo", poPass), "GetNextPurchaseOrder");

//this was just to see what the PO number was coming back.
poNumber = poPass[0].ToString();

//we continue
successCheck((int)poObject.InvokeMethod("nSetKey", poNumber), "SetKey");
object[] divisionNoObject = new object[] { "APDivisionNo$", "01" };
successCheck((int)poObject.InvokeMethod("nSetValue", divisionNoObject), "SetDivisionNo");
object[] vendorObject = new object[] { "VendorNo$", "AIRWAY" };
successCheck((int)poObject.InvokeMethod("nSetValue", vendorObject), "SetVendorNo");
object[] taxObject = new object[] { "TaxSchedule$", "NONTAX" };
successCheck((int)poObject.InvokeMethod("nSetValue", taxObject), "SetTaxSchedule");

DispatchObject poLines = new DispatchObject(poObject.GetProperty("oLines"));
successCheck((int)poLines.InvokeMethod("nAddLine"), "AddLine");
//object[] firstLine = new object[] { "ItemCode$", "/1." };
object[] firstLine = new object[] { "ItemCode$", "6655" };
successCheck((int)poLines.InvokeMethod("nSetValue", firstLine), "PoLineItemCode");
firstLine[0] = "QuantityOrdered";
firstLine[1] = "1";
successCheck((int)poLines.InvokeMethod("nSetValue", firstLine), "PoLineQuantityOrdered");
successCheck((int)poLines.InvokeMethod("nWrite"), "PoLinesWrite");
successCheck((int)poObject.InvokeMethod("nWrite"), "Write");

Console.WriteLine("SUCCESS! " + poNumber.ToString());

did you solved the problem? are you caable to receive a po?

did you solved the problem? are you caable to receive a po?

Yes, we are able to receive against PO's using the C# Dispatch Object through the BOI.  The code above shows what my final solution was.

in that solutions you insert a po did you insert a receipt of good agains po?

Yes, I am able to insert a receipt of goods against a PO.  Below is what we are using.  There will be stuff that is specific to us, but hopefully it helps.

using (DispatchObject pvx = new DispatchObject("ProvideX.Script"))
{
// Replace the text "*PATH TO MAS90\HOME*" with the correct MAS90\Home path in the line below
pvx.InvokeMethod("Init", @"***************");

using (DispatchObject oSS = new DispatchObject(pvx.InvokeMethod("NewObject", "SY_Session")))
{
try
{
int test = (int)oSS.InvokeMethod("nlogon");
if (test == 0)
{
test = (int)oSS.InvokeMethod("nSetUser", "****", "****");
}

if (test == 0)
{
errorMessage = Regex.Replace(oSS.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error logging in.");
}

oSS.InvokeMethod("nSetCompany", "***");
oSS.InvokeMethod("nSetDate", "P/O", DateTime.Now.ToString("yyyyMMdd"));
oSS.InvokeMethod("nSetModule", "P/O");

int TaskID = (int)oSS.InvokeMethod("nLookupTask", "PO_ReceiptofGoods_UI");
int setProgramTest = (int)oSS.InvokeMethod("nSetProgram", TaskID);

//we create two lists to store the line keys and quantities in.
ArrayList lineKeyList = new ArrayList();
ArrayList quantityList = new ArrayList();

using (DispatchObject poObject = new DispatchObject(pvx.InvokeMethod("NewObject", "PO_Receipt_bus", oSS.GetObject())))
{
string nextReceiptNo = "";
object[] nextReceiptObj = new object[] { nextReceiptNo };
int getNextReceiptTest = (int)poObject.InvokeMethodByRef("nGetNextReceiptNo", nextReceiptObj);
if (getNextReceiptTest == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error getting the next receipt.");
}

object[] passedObject = new object[] { "", "" };
passedObject[0] = "receiptNo$";
passedObject[1] = nextReceiptObj[0];
receiptNumber = nextReceiptObj[0].ToString();
int setReceiptNo = (int)poObject.InvokeMethodByRef("nSetKeyValue", passedObject);
if (setReceiptNo == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting a key value");
}
passedObject[0] = "ReceiptType$";
passedObject[1] = "G";
int setReceiptType = (int)poObject.InvokeMethodByRef("nSetKeyValue", passedObject);
if (setReceiptType == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the receipt type.");
}

passedObject[0] = "VendorNo$";
passedObject[1] = VendorNoHiddenField.Value.ToString();

if (VendorNoHiddenField.ToString().Equals(""))
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Vendor number hidden field is empty");
}

object[] batchObj = new object[] { BatchesComboBox.SelectedItem.ToString() };
int selectBatchTest = (int)poObject.InvokeMethodByRef("nSelectBatch", batchObj);
if (selectBatchTest == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error in setting the batch.");
}
int setKeyTest = (int)poObject.InvokeMethod("nSetKey");
if (setKeyTest == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the key.");
}

passedObject[0] = "PurchaseOrderNo$";
passedObject[1] = PONumberTB.Text;
int setPoNumber = (int)poObject.InvokeMethodByRef("nSetValue", passedObject);
if (setPoNumber == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the PoNumber value.");
}
passedObject[0] = "InvoiceNo$";
passedObject[1] = InvoiceTextBox.Text;
int setInvoiceNo = (int)poObject.InvokeMethodByRef("nSetValue", passedObject);
if (setInvoiceNo == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the Invoice No. value.");
}

passedObject[0] = "InvoiceDate$";
DateTime invoiceDateTime = (DateTime)InvoiceDatePicker.Value;
string modifiedInvoiceDate = invoiceDateTime.ToString("yyyyMMdd");

passedObject[1] = modifiedInvoiceDate;
int setInvoiceDate = (int)poObject.InvokeMethodByRef("nSetValue", passedObject);
if (setInvoiceDate == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the Invoice Date value.");
}

passedObject[0] = "Comment$";
if (CheckCommentsTB.Text.Length > 30)
passedObject[1] = CheckCommentsTB.Text.Substring(0, 30);
else
passedObject[1] = CheckCommentsTB.Text;

int setComments = (int)poObject.InvokeMethodByRef("nSetValue", passedObject);
if (setComments == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the check comments.");
}

try
{
using (DispatchObject poLines = new DispatchObject(poObject.GetProperty("oLines")))
{
//we first query the database to get all the line keys and quantitys.
if (con.State == ConnectionState.Closed)
{
con.ConnectionString = "Data Source=*****;Initial Catalog=****;Integrated Security=True;Pooling=False";
con.Open();
}
string getRequisitionItemsQuery = "Select * From RequisitionItem Where RequisitionNumber Like '" + RequisitionNumberLabel.Text + "';";
SqlCommand getReqItemsCmd = new SqlCommand(getRequisitionItemsQuery, con);
SqlDataReader getReqItemsDr = getReqItemsCmd.ExecuteReader();

while (getReqItemsDr.Read())
{
lineKeyList.Add(getReqItemsDr["PurchaseOrderLineKey"].ToString());
quantityList.Add(getReqItemsDr["QuantityReceived"].ToString());
quantityReceivedToDateList.Add(getReqItemsDr["QuantityReceivedToDate"].ToString());
}
getReqItemsDr.Close();
if (con.State == ConnectionState.Open)
con.Close();

passedObject[0] = PONumberTB.Text;
//the "1" value on the next line indicates copy all the lines and quantities. essentially complete the order.
passedObject[1] = 1;
int copyPOLinesTest = (int)poLines.InvokeMethodByRef("nCopyPurchaseOrderLines", passedObject);
if (copyPOLinesTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error in copying the po lines.");
}

int moveFirstTest = (int)poLines.InvokeMethod("nMoveFirst");
if (moveFirstTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error moving to the first line.");
}
string orderLineKeyString = "";
object[] lineKeyObject = new object[] { "OrderLineKey$", orderLineKeyString };
int getValueTest = (int)poLines.InvokeMethodByRef("nGetValue", lineKeyObject);
if (getValueTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error getting the first line key value.");
}
orderLineKeyString = lineKeyObject[1].ToString();

//now that we've got the lineKey value from above, we need to find the quantity that we want to receive at this point
double quantity = 0.0;
for (int i = 0; i < lineKeyList.Count; i++)
{
//if we've found the line key we are looking for
if (orderLineKeyString.Equals(lineKeyList[i].ToString()))
{
//set the quantity to the corresponding value in the quantity list
quantity = double.Parse(quantityList[i].ToString());
//get out of the for loop
break;
}
}

passedObject[0] = "QuantityReceived";
passedObject[1] = quantity;
double quantityOrdered = 0.0;
object[] quantityOrderedObject = new object[] { "QuantityOrdered", quantityOrdered };
int gettingQuantityOrderedTest = (int)poLines.InvokeMethodByRef("nGetValue", quantityOrderedObject);
if (gettingQuantityOrderedTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error getting the quantity ordered.");
}
quantityOrdered = double.Parse(quantityOrderedObject[1].ToString());

int setQuantityReceivedTest2 = (int)poLines.InvokeMethodByRef("nSetValue", passedObject);
if (setQuantityReceivedTest2 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the quantity received for the first line..");
}

int writeFirstLineTest = (int)poLines.InvokeMethod("nWrite");
if (writeFirstLineTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error writing the first line.");
}

int moveNextLineTest = (int)poLines.InvokeMethod("nMoveNext");
if (moveNextLineTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error moving to the next line after writing the first.");
}
int getValueTest2 = (int)poLines.InvokeMethodByRef("nGetValue", lineKeyObject);
if (getValueTest2 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error getting the value when moving to the second line.");
}
string nextLineKey = orderLineKeyString;

if (!nextLineKey.Equals(lineKeyObject[1].ToString()))
{
while (!nextLineKey.Equals(lineKeyObject[1].ToString()))
{
nextLineKey = lineKeyObject[1].ToString();
passedObject[0] = "QuantityReceived";
//find the quantity associated with that line key
for (int i = 0; i < lineKeyList.Count; i++)
{
//again, if we've found the line key we are looking for
if (nextLineKey.Equals(lineKeyList[i].ToString()))
{
//set the appropriate quantity value
quantity = double.Parse(quantityList[i].ToString());
//get out of the for loop for now
break;
}
}

passedObject[1] = quantity;
double quantityOrdered2 = 0.0;
object[] quantityOrderedObject2 = new object[] { "QuantityOrdered", quantityOrdered2 };
int gettingQuantityOrderedTest2 = (int)poLines.InvokeMethodByRef("nGetValue", quantityOrderedObject2);
if (gettingQuantityOrderedTest2 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error getting the quantity ordered.");
}
quantityOrdered2 = double.Parse(quantityOrderedObject[1].ToString());

int setQuantityReceivedTest1 = (int)poLines.InvokeMethodByRef("nSetValue", passedObject);
if (setQuantityReceivedTest1 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error setting the quantity received.");
}

int writeLineTest = (int)poLines.InvokeMethod("nWrite");
if (writeLineTest == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error in writing the po line.");
}
int moveNextLineTest2 = (int)poLines.InvokeMethod("nMoveNext");
if (moveNextLineTest2 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error in moving to the next line.");
}
int getValueTest3 = (int)poLines.InvokeMethodByRef("nGetValue", lineKeyObject);
if (getValueTest3 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error getting the next line key value.");
}

}
}
int writeLineTest2 = (int)poLines.InvokeMethod("nWrite");
if (writeLineTest2 == 0)
{
errorMessage = Regex.Replace(poLines.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error writing the po line.");
}

}
int writePOObjectTest = (int)poObject.InvokeMethod("nWrite");
if (writePOObjectTest == 0)
{
errorMessage = Regex.Replace(poObject.InvokeMethod("sLastErrorMsg").ToString(), "'", "");
throw new System.Exception("Error writing the PO Object.");
}

}
catch (Exception ex)
{

}
}

}
catch (Exception ex)
{

}
}
}