document.getElementById("prdAntal").value

^ That line gets the quantity number from the input-field.

This script is executed on keyup and it displays the total price for the product in a div.
Is there any way I can make it faster?
I appreciate all suggestions.

Parameters,

"prisDiv" is the div where the total price will be displayed.
"pris" is the price of the product.


Variables,

"antalPrd" = that gets the number of how many quantity-input fields there is. (just so I can calculate all products)
"prdSumma" = total price of the product. (Quantity * Price)
"moms" = VAT
"totalt" = the absolute total price for all the total prices. (lol)


function editPris(prisDiv,pris) {
	var antalPrd = document.getElementById("prdAntal").value;
	var prdSumma = 0;
	var moms = 0;
	var totalt = 0;
	if(document.getElementById(prisDiv+"_input").value != ""){
		if(!isNaN(document.getElementById(prisDiv+"_input").value)){
			document.getElementById(prisDiv).innerHTML=" ("+document.getElementById(prisDiv+"_input").value*pris+" kr)";
		}else{
			document.getElementById(prisDiv).innerHTML=" (0 kr)";
		}
		document.getElementById(prisDiv).style.display = "block";
		for (i=0;i<=antalPrd;i++){
			var x = parseInt(document.getElementById("prdPris"+i).value);
			var y = parseInt(document.getElementById("pris"+i+"_input").value);
			if(isNaN(x)){ x=0; }
			if(isNaN(y)){ y=0; }
			prdSumma += x*y;
			moms = prdSumma * 0.25;
			totalt = prdSumma + moms;
			document.getElementById("summa").innerHTML=prdSumma+"&nbsp;kr";
			document.getElementById("moms").innerHTML=moms+"&nbsp;kr";
			document.getElementById("totalt").innerHTML=totalt+"&nbsp;kr";
		}
	}else{
		document.getElementById(prisDiv).innerHTML="&nbsp;(0)";
		document.getElementById(prisDiv).style.display = "none";
		for (i=0;i<=antalPrd;i++){
			var x = parseInt(document.getElementById("prdPris"+i).value);
			var y = parseInt(document.getElementById("pris"+i+"_input").value);
			if(isNaN(x)){ x=0; }
			if(isNaN(y)){ y=0; }
			prdSumma += x*y;
			moms = prdSumma * 0.25;
			totalt = prdSumma + moms;
			document.getElementById("summa").innerHTML=prdSumma+"&nbsp;kr";
			document.getElementById("moms").innerHTML=moms+"&nbsp;kr";
			document.getElementById("totalt").innerHTML=totalt+"&nbsp;kr";
		}
	}
}