function exchange(type_id,item,item_id,price)
{
	if(confirm("是否真的购买该物品吗?") )
	{
		var myAjax = new Ajax.Request
		(
			'exchange.php',
			{
				method:'post',
				parameters:"type_id=" + type_id + "&item=" + item +"&item_id=" + item_id +"&price=" + price,
				asynchronous:true,
				onSuccess:function(transport)
				{
					var result = transport.responseText;
					alert(result);
					/*
					if (result==true)
					{
						alert("恭喜你,购买成功!");
					}
					else
					{
						alert("购买失败,请确认是否登陆或是否有余额!");
					}
					*/
				}								   
			}
		);
	}
}