Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript">
const debit_fee=0.20;
const store_fee=0.12;
const regular_fee=500;
var numericExpression =/^[0-9.]+$/;
var item_cost=document.getelementbyid('itemcost').value;
function calculate()
{
	if(item_cost.match(numericExpression) )
{
	for(i=0;i<=document.getElementsByName('method').length;++i)
  {
	if(document.getElementsByName('method')[i].checked)
	{
	var radio_value=document.getElementsByName('method')[i].value;
	break;
	}
  }
  switch(radio_value)
  {
	  case "credit_card":
	  var total=(item_cost+regular_fee)*debit_fee;
	  break;
	  case "Regular":
	  var total=(item_cost+regular_fee)*store_fee;
	  break;
	  default:
	  alert('Please Select a Payment Method You wish to use');  
  }
  document.getElementById("total").value=total;
}
else
alert('Please Enter only Numeric Values For the Item Cost');
}
</script>
<style>
#purchaseCalculator
{
	margin:0 auto;
	border: 1px solid #666;
	min-height:200px;
	max-width:400px;
	text-align:center;
}
</style>
</head>
<body>
<div id="purchaseCalculator">
<form>
<label>Item Cost</label><input type="text" id="itemcost"/><br />
<p>Select Payment Method</p>
<label>Credit Card</label><input type="radio" name="method" value="credit_card" />
<label>Regular Purchase</label><input type="radio" name="method" value="Regular" /><br />
<input type="button" value="Calculate" onclick="calculate()" style="text-align:center;" /><br />
<label>Total:<input type="text" name="Total" id="total" />
</form>
</div>
</body>
</html>
anybody willing to tell me why thsi is not working. it says the item cost is undifined and when i hard code it a value it says my match function does not exist though i am sure it works as i have used it b4......and help appreciated and i already know the loop says undifined when nothing is selected but it does not show my aler error