function login(blValidate)
{
  var ajax = initAjax();
  
　var form = document.getElementById("userLogin");
　var userName = form.TxtUserName.value;
　var passWord = form.TxtPassWord.value;
　var valiDate = "";
　
　if(userName == "")
　{
　		alert("提示：请输入用户名！");
　		form.TxtUserName.focus();
　		return;
　}
　
　if(passWord == "")
　{
　		alert("提示：请输入密码！");
　		form.TxtPassWord.focus();
　		return;
　}
　
　if(blValidate==true)
　{
　		valiDate = form.TxtValidate.value;
　		
　		if(valiDate == "")
　		{
　			alert("提示：请输入验证码！");
　			form.TxtValidate.focus();
　			return;
　		}
　}
　
　var url = "/Controls/UserLogin.aspx";
　var postStr = "TxtUserName="+ userName +"&TxtPassWord="+ passWord + "&TxtValidate="+ valiDate + "&blValidate="+ blValidate;
　
　ajax.open("POST", url, true);
　ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
  ajax.onreadystatechange = function()
　{
		if(ajax.readyState == 4 && ajax.status == 200)
		{
			if(ajax.responseText=="")
			{
				document.location.href="/User/";
			}
			else
			{
				alert(ajax.responseText);
			}
			document.getElementById("msg").innerHTML = "";
			document.getElementById("btnLogin").disabled=false;
		}
		else
		{
			document.getElementById("btnLogin").disabled=true;
			document.getElementById("msg").innerHTML = "<img src='/Images/ajax-loader.gif' />";
		}
　}
　
　ajax.send(postStr);
}