I'm assuming you are referencing your query in the Rowsource property of the combobox. If that is true, a simple query wont look at your form to determine the value of your txtAcctType textbox. When you click the combobox does it give you a pop up asking for the value of txtAcctType?
You need to use some code. Add this code to you form. Replace Combo1 with the name of your combo box. Add line breaks in queries as needed.
Code:
Private Sub Combo1_GotFocus()
Combo1.RowSourceType = "Table/Query"
If txtAcctType.Value = 1 Or txtAcctType.Value = 2 Then
Combo1.RowSource = "SELECT TblReports.LetterName, TblReports.ScreenName,TblReports.RptNo, TblReports.EmpType
FROM TblReports
WHERE TblReports.EmpType="RO" ORDER BY TblReports.ScreenName"
Else
Combo1.RowSource = "SELECT TblReports.LetterName, TblReports.ScreenName,TblReports.RptNo, TblReports.EmpType
FROM TblReports
WHERE tblReport.RptNo<>144 and TblReports.EmpType="RO" ORDER BY TblReports.ScreenName"
End If
End Sub
Hope this helps.