Im assuming you have 18 text boxes and need to validate it. If so, this is the code for it.
Lets say you have text1 - text18.
For i = 1 to 18
If texti.text = "" then
Msgbox("Error! Field not Filled")
End if
Next
5 Lines for 18 boxes
But if you have names for the textboxes, it gets more complicated o_O
Have a button called "Submit" or something, and This should be its coding -
If txtname1.text <> "" and txtname2.text <> "" and .................. and txtname18.text <> "" Then
(Put in whatever should happen, like the combo boxes get enabled, etc")
End If
Hope this helps o_O