/**
	shopping_cart.js - JavaScript functions to manage the shopping cart
 **/

// flag to indicate when qty has been changed but price has not been updated 
cart_dirty = false;

function validate_cart(form) {
	for (i=0; i<form.elements.length; i++) {
		if ((form.elements[i].type == 'select-one') && form.elements[i].name.indexOf("item") == 0) {
			if (form.elements[i].value == -1) {
				alert('Please select a size for all images before checking out.');
				return false;
			}
		}
	}
	
	if (cart_dirty) {
		alert('Please click Update Cart to update your order total before checking out.');
		return false;
	}
	
	return true;
}

function qty_changed() {
	cart_dirty = true;
}

function update_cart(form) {
	form.action = "show_cart.php";
	form.update_qty.value='true';
	cart_dirty=false;
	form.submit();
}

function checkout(form) {
	if (validate_cart(form)) {
		form.submit();
	} else 
		return false;
	
}

/* If the ENTER key was pressed, submit the form */
function handleEnterSubmission (field, evt, form) {
	 var keyCode = evt.which ? evt.which : evt.keyCode;
     if (keyCode == 13) {
        update_cart(form);

       /* field.form.submit(); */
       return false;
     }
     else {
     	qty_changed();
       	return true;
     }
   }