If Salary for February month  is 50000  so i usually deduct 1303 as TDS and Credit 48697 as salary to my Staff but this time I have Deducted 20000 as Advance which is taken on October and also Deducted 1303 tds and Credited 28697 as salary this way of calculation is correct or wrong ? When i deduct Advance salary amount will become less then the tds amount will differ or not?