Try this:
Code:
Private Sub lstQuerySelection_Click()
On Error GoTo ErrorHappened
Dim strQuerySelection As String
Dim dbsPSU1 As DAO.Database
Dim rs As DAO.Recordset
If lstQuerySelection.ListIndex <> -1 Then
strQuerySelection = "[" & lstQuerySelection.ItemData(lstQuerySelection.ListIndex) & "]"
Else
GoTo ExitNow
End If
Set dbsPSU1 = CurrentDb
strSQL = "SELECT DISTINCT " & strQuerySelection & " FROM PSU WHERE nz(" & strQuerySelection & ","""") <> """" ORDER BY " & strQuerySelection & " ASC"
Set rs = dbsPSU1.OpenRecordset(strSQL, dbOpenSnapshot)
If rs.EOF Then
MsgBox "No matches found; Please check your criteria", vbInformation + vbOKOnly, "PSU Query"
GoTo ExitNow
End If
lstQueryResults.RowSource = ""
Do While Not rs.EOF
lstQueryResults.AddItem rs.Fields(0)
rs.MoveNext
Loop
ExitNow:
On Error Resume Next
rs.Close
Set rs = Nothing
Set dbsPSU1 = Nothing
Exit Sub
ErrorHappened:
MsgBox "Error " & Err.Number & " (" & Err.Description & ")"
Resume ExitNow
End Sub