swal弹框后input标签获得焦点

swal({ 
    title: "用户名", 
    text: "用户名不能为空", 
    type: "error", 
    showCancelButton: true, 
    closeOnConfirm: false, 
    confirmButtonText: "我知道了", 
    confirmButtonColor: "#ec6c62" 
}, function() { 
setTimeout(function(){$("#username").focus();},0);
   

});