I have tested that having a '_bus' entry in the Data Dictionary (DD) maintenance 'Business Object' field doesn't mean the table is writable.

For example: 'AP_InvoiceHistoryHeader' has 'AP_InvoiceHistory_bus' shown in the DD as its Business Object, but after successful nSetKeyValue (using InvoiceNo & HeaderSeqNo), nSetKey and nSetValue using that BO - causes an nWrite returns a zero! (i.e. read only - see sample program below).

How do I tell (preferably programmatically) which business objects are writable and what their UI object names are for use with nSetProgram and nLookupTask respectively?

Dim oSS: Dim oScript: Dim oBus
Dim retVal : retVal = 0
Dim sCommentWas : sCommentWas = ""

Set oScript = CreateObject("ProvideX.Script")
oScript.Init ("C:\Sage\Sage 100 Standard ERP\MAS90\Home")
Set oSS = oScript.NewObject("SY_Session")
retVal = oSS.nLogon()
retVal = oSS.nSetUser("user", "password")
retVal = oSS.nSetCompany("ABC")

retVal = oSS.nSetProgram(oSS.NlookupTask("AP_InvoiceHistory_ui"))

Set oBus = oScript.NewObject("AP_InvoiceHistory_bus", oSS)

retVal = oBus.nSetKeyValue("InvoiceNo$", "1050190")   'retVal = 1
retVal = oBus.nSetKeyValue("HeaderSeqNo$", "000000")  'retVal = 1
retVal = oBus.nSetKey()                               'retVal = 1
sCommentWas = ""
retVal = oBus.nGetValue("Comment$", sCommentWas)      'retVal = 1
retVal = oBus.nSetValue("Comment$", "Testing")        'retVal = 1
retVal = oBus.nWrite()                                'retVal = 0