asp.net - javascript calculation not giving desired out put -

i have following code

 function calculatevat() {         var vat = null;var amount=null;         vat = document.getelementbyid("hiddenvat").value;                    amount = document.getelementbyid("numtxt_itemcost").value;         var total = parseint(amount)* parseint(vat) / 100 ;          document.getelementbyid("txt_total_text").value = total;     } 

here calculating vat price according amount price

e.g vat value 13.5

if input 1780 on numtxt_itemcost field should give output 240.30

but when run programme puting value 1780 on numtxt_itemcost field

it shows 231.4 wrong output

help please urgent!!

you should use parsefloat instead:

parsefloat(1780)* parsefloat(13.5) / 100 //240.3 

when use parseint, decimals stripped off.