function initialize() {
	addButton = document.getElementById("addButton");
	qtyField = document.getElementById("qty");
	if (addButton != null) {
		addButton.onclick = addToCart;
	}
	form = document.getElementById("addToCart");
}

function checkForDigitOnly(e) {
	e = (e) ? e : event;
	var charCode = (e.charCode) ? e.charCode : ((e.keyCode) ? e.keyCode : ((e.which) ? e.which : 0)); 
	
	if (charCode > 31 && (charCode < 48 || charCode > 57)) {
		alert("Enter numbers only in the Quantity field.");
		return false;
	}
	
	return true;
}

function addToCart() {
	addButton.disabled = true;
	form.action = location.href;
	form.submit();
	return false;
}

var form, qtyField, addButton;
window.onload = initialize;