Hi Michael,
>-- snip of code---
> sele sites
> seek allt(this.value)
> If !found()
> wait wind "SITE# not found" NOWAIT
> NODEFAULT &&will prevent the focus from leaving the entry box
> Endif
> thisform.refresh &&will update the display of field values
>--- end of code snip ---

What does this.value hold. If it's numeric, the error is in allt(this.value).

To verify where the problem is, you should probably activate the debugger by adding these two lines before the code above:

activate window trace
suspend

You can then step through the code line by line and discover easily where the problem is.

Best.

Matt.