jquery ajax

function submitForm(){
			var submitUrl = url;
			$.ajax({
				type: "POST",
				url: submitUrl,
				data: {
					"loginUser.user_name": $("#UserName").val()
				  , "user.password": $("#password").val()
				  , "randCode": $("#randCode").val()
				},
				beforeSend: function( xhr ) {
					try{
						xhr.setRequestHeader('X-Requested-With', {toString: function(){ return ''; }});
						xhr.setRequestHeader('Cache-Control', 'max-age=0');
						xhr.setRequestHeader('Accept', 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8');
					}catch(e){};
				},
				timeout: 30000,
				//cache: false,
				//async: false,
				success: function(msg){
					//密码输入错误
					//您的用户已经被锁定
					if ( msg.indexOf('请输入正确的验证码') > -1 ) {
						alert('请输入正确的验证码！');
					} else if ( msg.indexOf('当前访问用户过多') > -1 ){
						reLogin();
					} else if( msg.match(/var\s+isLogin\s*=\s*true/i) ) {
						notify('登录成功，开始查询车票吧！');
						window.location.replace( queryurl );
					} else {
						msg = msg.match(/var\s+message\s*=\s*"([^"]*)/);
						if( msg && msg[1] ) {
							alert( msg && msg[1] );
						} else {
							reLogin();
						}
					}
				},
				error: function(msg){
					reLogin();
				}
			});
		}