function ReSet()
{
   for(var i=0;i<form1.elements.length;i++)
   {
	  if(form1.elements[i].tagName=="INPUT")
	  {
		  if(form1.elements[i].type=="text")
		  {
			  form1.elements[i].value="";
		  }
	  }
   }
}
//验证单表单不能为空
function Check_Form()
{
   if(document.getElementById("txtUserName") && Trim(document.getElementById("txtUserName").value) =="")
	{
		alert('用户名不能为空！');
		return false;
	}
	if(document.getElementById("txtPassword") && Trim(document.getElementById("txtPassword").value) =="")
	{
		alert('密码不能为空！');
		return false;
	}
	else
	{
		var url="ajax/checkusername.aspx?type=login&username="+encodeURIComponent(Trim(document.getElementById("txtUserName").value))+"&password="+encodeURIComponent(Trim(document.getElementById("txtPassword").value))+"&time="+new Date().getTime();
		var response=httpRequest("get",null,url);
		if(response!="true")
		{
			alert(response);
			document.getElementById("txtUserName").select();
			document.getElementById("txtPassword").value="";
			return false;
		}
		else
		{
		    window.location.href="index.aspx";	
		}
	}
}