// JavaScript Document
function check(){
	if(document.getElementById("receiver").value=="")
	{
	alert("请输入您的姓名！");
	document.getElementById("receiver").focus();
	return false;
	}
	if(document.getElementById("phone").value=="" && document.getElementById("email").value=="")
	{
	alert("邮箱和联系方式二选一，必填一个！");
	document.getElementById("phone").focus();
	return false;
	}
	if(document.getElementById("email").value!="" && (document.getElementById("email").value.indexOf("@")<0 || document.getElementById("email").value.indexOf(".")<3))
	{
	alert("邮箱格式错误！请重新输入");
	document.getElementById("email").focus();
	return false;
	}
	if(document.getElementById("content").value=="")
	{
	alert("请输入留言内容！");
	document.getElementById("content").focus();
	return false;
	}
	return true;
}