function recalculate(){
	var sum=0;
	
	// calculate the permit renewal total
	if(document.tennis_renewal_order2.is_permit_checked.checked){
		var selTypePos = getSelectedTypePos();
		document.tennis_renewal_order2.elements[selTypePos].checked=true;
		
		var typeName = document.tennis_renewal_order2.elements[selTypePos].value;
		if(typeName=="junior"){
			document.tennis_renewal_order2.tennis_renewal_total.value="10";
		}
		else if(typeName=="adult"){
			document.tennis_renewal_order2.tennis_renewal_total.value="100";
		}
		else if(typeName=="senior"){
			document.tennis_renewal_order2.tennis_renewal_total.value="20";
		}
	}
	else{
		document.tennis_renewal_order2.tennis_renewal_total.value="0";
	}
	
	// calculate the locker reservation total
	if(document.tennis_renewal_order2.is_locker_reservation_checked.checked){
		document.tennis_renewal_order2.locker_reservation_total.value="20.00";
	}
	else{
		document.tennis_renewal_order2.locker_reservation_total.value="0";
	}

	// calculate the single play total
  if(document.tennis_renewal_order2.is_single_play_checked.checked){
  	if(document.tennis_renewal_order2.single_play_quantity.value==null 
  	  ||document.tennis_renewal_order2.single_play_quantity.value==""
  	  ||document.tennis_renewal_order2.single_play_quantity.value=="0"){
  		document.tennis_renewal_order2.single_play_quantity.value=1;
  	}
  	// make sure it is a number
  	if(isNaN(parseInt(document.tennis_renewal_order2.single_play_quantity.value, 10)))
  	  document.tennis_renewal_order2.single_play_quantity.value=1;
  	
  	var t = parseInt(document.tennis_renewal_order2.single_play_quantity.value, 10)*7;
  	document.tennis_renewal_order2.single_play_total.value=t;
  }
  else {
  	document.tennis_renewal_order2.single_play_total.value=0;
  }
  
	// calculate the reservation ticket total
  if(document.tennis_renewal_order2.is_tennis_reservation_checked.checked){
  	if(document.tennis_renewal_order2.tennis_reservation_quantity.value==null 
  	  ||document.tennis_renewal_order2.tennis_reservation_quantity.value==""
  	  ||document.tennis_renewal_order2.tennis_reservation_quantity.value=="0"){
  		document.tennis_renewal_order2.tennis_reservation_quantity.value=1;
  	}
  	// check to see if it is a number
  	// make sure it is a number
  	if(isNaN(parseInt(document.tennis_renewal_order2.tennis_reservation_quantity.value, 10)))
  	  document.tennis_renewal_order2.tennis_reservation_quantity.value=1;
  	
  	var t = parseInt(document.tennis_renewal_order2.tennis_reservation_quantity.value, 10)*7;
  	document.tennis_renewal_order2.tennis_reservation_total.value=t;
  }
  else {
  	document.tennis_renewal_order2.tennis_reservation_total.value=0;
  }

  // calculate the sum
  sum=sum+parseFloat(document.tennis_renewal_order2.tennis_renewal_total.value, 10);
  sum=sum+parseFloat(document.tennis_renewal_order2.locker_reservation_total.value, 10);
  sum=sum+parseFloat(document.tennis_renewal_order2.single_play_total.value, 10);
  sum=sum+parseFloat(document.tennis_renewal_order2.tennis_reservation_total.value, 10);
  sum=Math.round(sum*100)/100;
  
  document.tennis_renewal_order2.amount.value=sum;
}

function getSelectedTypePos(){
	var selPos=0;
  for(var i=0; i<document.tennis_renewal_order2.elements.length; i++){
		if(document.tennis_renewal_order2.elements[i].value=="junior"){
			if(document.tennis_renewal_order2.elements[i].checked){
				selPos=i;
			}
		}
		else if(document.tennis_renewal_order2.elements[i].value=="adult"){
			if(document.tennis_renewal_order2.elements[i].checked){
				selPos=i;
			}
			else if(selPos==0){ // get adult position for later use
				selPos=i;
			}
		}
		else if(document.tennis_renewal_order2.elements[i].value=="senior"){
	  	if(document.tennis_renewal_order2.elements[i].checked){
	    	selPos=i;
	    }
		}
	}
  return selPos;		
}

function chkTotal(){
	recalculate();
	if(document.tennis_renewal_order2.amount.value=="" || document.tennis_renewal_order2.amount.value=="0"){
		alert("Please select the items you would like to purchase.");
		return false;
	}
  if(parseFloat(document.tennis_renewal_order2.amount.value, 10)>250){
		alert("The grand total of your purchase cannot exceed $250 for security reasons.  Please modify your selections accordingly.");
		return false;
	}
	return true;
}