>SIR,
>
>I am facing a problem about valid event in grid.
>
>The form is attached, please help
>
>http://www.foxite.com/uploads/5112e621-57aa-4bca-819d-de184254e6d3.zip

You are moving the record pointer explicitly yourself using 'count' command.

if !empty(this.value)
	LOCAL ARRAY cct[1]
	SELECT COUNT(*) FROM subjects where sno = this.Value  into ARRAY cct
	RETURN ( cct[1] <= 1 )
endif

Cetin