hi,
here is a little technique i use for that.
at the start of the sub...
If IsNull(Me!txtControlNbr) Then
MsgBox (" Enter a Control Number.")
Exit Sub
Else
If IsNull(Me!txtVendorName) Then
Msbbox(" Enter a vendor")
Me!txtVendorName.SetFocus
Exit Sub
Else
If IsNull(Me!txtBuyer) Then
Me!txtBuyer.SetFocus
Msgbox(" Enter a buyer.")
Exit Sub
End If
End If
end if
rest of main code goes here.
If my users don't enter a control number or a vendor or a
buyer, then they don't get to go any further because
unless they do, you have the code to exit the sub before
they get to the main code.
the above sniplit is from code i use and it works. you may
need to modify it some to fit your situation. it may not
work as is but maybe it will give you ideas.
good luck.