I used VFP3.0B. Does the following code correct if it run in VFP5.0?
The textbox is bound to a field which data type is numeric.

DEFINE CLASS txtTest AS Textbox
     PROCEDURE Valid
          IF This.Text > '90'              && Is it correct?
               Wait 'Range Over' Window NoWait NoClear
               RETURN 0
          ENDIF
     ENDPROC
ENDDEFINE