Validate and filter incorrect parameters.

Lets say your variable for the sting is SearchString

Function Test()

Dim SearchString As String
Dim Cnt
Dim ValChar

SearchString = "Te/t"

Cnt = 1

Do While Cnt <= Len(SearchString)
ValChar = Mid(SearchString, Cnt, 1)
If IsNumeric(ValChar) Then
MsgBox (&quot;Good Charater&quot
ElseIf ValChar >= &quot;A&quot; And ValChar <= &quot;Z&quot; Then
MsgBox (&quot;Good Charater&quot
Else
MsgBox (&quot;Bad Charater&quot
End If
Cnt = Cnt + 1
Loop

End Function

Let's say your user entry control is named txtFind.

You could use code something like this. It first checks to see if there is data in the control txtFind. If there is it looks for a value not equal to 0 and assumes that a numeric value is entered, otherwise it looks for a text value.

If IsNull(me.txtFind) then
msgbox &quot;No parameter entered!&quot;
Exit Sub
Else
If val(me.txtFind) <> 0 then
'put your code for the numeric search here
End If
If me.txtFind Between &quot;A&quot; and &quot;ZZZZZZZZZZZZZ&quot; then
'put your code for the text search here
End If
End If

You might change the second test to read

If mid(me.txtFind,1,1) Between &quot;A&quot; and &quot;Z&quot; then

Access ignores the case of text unless specifically told to check the case. If 0 is a valid numeric entry, then the first statement should read:

If val(me.txtFind) <> 0 or me.txtFind = &quot;0&quot; then

(note that this is a zero, not a capital O)