// JavaScript Document
/***********************************************
* Required field(s) validation v1.10- By NavSurf
* Visit Nav Surf at http://navsurf.com
* Visit http://www.dynamicdrive.com/ for full source code
***********************************************/
function handleEnter (field, event) {
		var keyCode = event.keyCode ? event.keyCode : event.which ? event.which : event.charCode;
		if (keyCode == 13) {
			var i;
			for (i = 0; i < field.form.elements.length; i++)
				if (field == field.form.elements[i])
					break;
			i = (i + 1) % field.form.elements.length;
			field.form.elements[i].focus();
			return false;
		} 
		else
		return true;
}

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Created by: www.jdstiles.com -->
<!-- Begin
function startCalc(){
  interval = setInterval("calc()",1);
}

function calc(){
  quantity1 = 1.0 * document.polos_order.Qty1Field.value;
  quantity2 = 1.0 * document.polos_order.Qty2Field.value;
  quantity3 = 1.0 * document.polos_order.Qty3Field.value;
  quantity4 = 1.0 * document.polos_order.Qty4Field.value;
  quantity5 = 1.0 * document.polos_order.Qty5Field.value;
	var totalquantity;
	totalquantity	 = 0.0;
	totalquantity+= quantity1;
	totalquantity+= quantity2;
	totalquantity+= quantity3;
	totalquantity+= quantity4;
	totalquantity+= quantity5;
	if (totalquantity > 1){price = 18};
	else price = 20;
  document.polos_order.TotalPriceField.value = totalquantity * price * 1.0;
}

function stopCalc(){
  clearInterval(interval);
}