function fixTo(number,i){
var y = Math.pow(10,i);
number = number * y;
number = Math.round(number) / y;
var x = number.toFixed(i);
return x;
}
function setSumById(start){
var total=0;
$("[id^='"+start+"']").each(function (){
if($(this).text()!="")
total+=parseFloat($(this).text());
});
$("#sum_"+start).html(fixTo(total,2));
}