function check_add_cart() {
	//function ensures a valid quantity value is entered before submitting//
	var TempQuantity=form_return_value('TrolleyAdd','quantity');
	if ((form_get_value('TrolleyAdd','quantity')==false) || (form_check_numerical('TrolleyAdd','quantity')>0) || (parseInt(TempQuantity)<1)) {
		alert("Please enter a valid quantity in the field provided.");
		set_focus('TrolleyAdd','quantity'); }
	else {
		update_total_cost();
		document.TrolleyAdd.submit();
	}
}

function check_add_cart_update(id_num) {
	//checking updating of existing quantity of product in trolley//
	var TempQuantity=form_return_value('TrolleyView','quantity_'+id_num);
	if ((form_get_value('TrolleyView','quantity_'+id_num)==false) || (form_check_numerical('TrolleyView','quantity_'+id_num)>0) || (parseInt(TempQuantity)<1)) {
		alert("Please enter a valid quantity.");
		set_focus('TrolleyView','quantity_'+id_num); }
	else {
		document.TrolleyViewUpdate.ProductTrolleyId.value=id_num;
		document.TrolleyViewUpdate.ProductQuantity.value=form_return_value('TrolleyView','quantity_'+id_num);
		document.TrolleyViewUpdate.ProductNotes.value=form_return_value('TrolleyView','notes_'+id_num);
		document.TrolleyViewUpdate.submit();
	}
}

function remove_cart_item(trolley_id_num,current_page,current_action,current_id) {
	//call remove from shopping trolley//
	self.location=current_page+"?pxa="+current_action+"&id="+current_id+"&pxc=remove_item&pxb="+trolley_id_num;
}

function add_cart_quick_link(id_num) {
	document.AddTrolley.QuickProductId.value=id_num;
	document.AddTrolley.submit();
}

function update_total_cost() {
	//ensure entered quantity is valid//
	if ((form_get_value('TrolleyAdd','quantity')==true) && (form_check_numerical('TrolleyAdd','quantity')==0)) {
		var ProductQuantity=form_return_value('TrolleyAdd','quantity');

		if (PricingExist) {
			if (id_array_multiple_exists) {
				//More than one purchase option exists for current product//
				//get price entry based on selected option//
				var SelectedOption=document.TrolleyAdd.size_select.selectedIndex;
				//alert("SelectedOption: "+SelectedOption);

				//get cost from pricing array - remove ' from value//
				var SelectedOptionPrice=string_remove_quotes(price_array[SelectedOption]);
				//alert("SelectedOptionPrice: "+SelectedOptionPrice);

			}
			else {
				//Single pricing option exists//
				var SelectedOptionPrice=string_remove_quotes(price_array[0]);
				//alert("SelectedOptionPrice: "+SelectedOptionPrice);
			}

			//calculate total for quantity//
			var PriceTotal=SelectedOptionPrice*ProductQuantity;

			//update form field display//
			document.TrolleyAdd.price_total.value=PriceTotal;
		}
	}
}