You can acomplish that with a couple of functions.

lcStr = "123RTY234"
? LEN(CHRTRAN(lcStr, "1234567890", "")) = 0

>VFP 6.0: Is there any function to display if my string is non numeric?
>ie:
>string: 123RTY234 (non numeric)
>string: FHE1234 (non n)
>string: 121345 (numeric)
>
>IsDigit() look only the first char...
>Val() returns zero if first char. is alphab.
>
>I would like to know if there is any NATIVE FUNCTION, if not.... I have to create one.
>Thanks