/**
 * Change default the product qty to user-defined qty.
 * 
 * @param product_id -
 *            Id of product
 * @return false;
 */
function onClick_editProductQty(product_id) {
	var button_name = "a[rel='ajax_id_product_" + product_id + "']";
	var qty = jQuery.trim($("#product_qty_" + product_id).attr("value"));
	if (qty == "")
		qty = "1";
	var link = $(button_name).attr("href");
	link = link.replace("qty=1", "qty=" + qty);
	$(button_name).attr("href", link);
	//$("#product_qty_" + product_id).attr("value", "");// clear qty value
	return false;
}