How to calculate and show the leave balance and display it when user logs in ASP.Net

CREATE PROCEDURE [].[]

@fname VARCHAR(20)

,@noofleave int

as

begin

DECLARE @AvailableLeave INT

SELECT  @AvailableLeave =AvailableLeave from tbl where fname=@fname

if @AvailableLeave  > 0

UPDATE tble

SET AvailableLeave=AvailableLeave-noofleave

where

fname=@fname

end

Please make a look in to it.