>Hi All,
>
>I have a textbox where the only valid input is C, E, I or S. I had seen somewhere here a quick 1 line of code way to test for this. But it eludes me. Could someone please jog my memory?
>
>TIA
Hi Mike,

You can put 'M C,E,I,S' into the texbox format property and user wouldn't be able to enter anything else. Otherwise

llOk = INLIST( This.Value, "C", "E", "I", "S")
*OR 
llOk =  This.Value $  "CEIS")