ajax方式验证登录系统

/**

*/

('#sel_user').bind('keypress',function(event){
if(event.keyCode == '13'){
$("password").focus();
}
});

$('#password').bind('keypress',function(event){
    if(event.keyCode == '13'){
        login_act();
    }
});
 
$('#loading').hide();

});

/登录/
function login_act() {
var user = ('#userid').focus();
return;
}

var pwd = $.trim($("#password").val());
if (pwd == '') {
    alert('密码不能为空');
    $('#password').focus();
    return;
}
 
$('#loading').show();
 
$.ajax({
    type : "POST",
    url : "login_validate.php",
    data : "act=login" + "&userid=" + user + '&password=' + pwd,
    dataType : "json",
    async : false,
    cache : false,
    success : function(data) {
         
        $('#loading').hide();
         
        if (data['ans'] == 'ok') {

// window.location.href = '../main/index.php';//直接跳转
//延迟100毫秒 跳转
setTimeout(function(){
window.location.href = '../main/index.php';
return false;//阻止冒泡
},100);
} else {
alert(data['ans']);
return false;
}
},
error : function(e, jqxhr, settings, exception) {
$('#loading').hide();
alert('服务器繁忙');
}
});
}