用 javascript 实现简单的信息提示

//样式部分

.message {

    position: fixed;top: -100px;width: 400px;left: 50%;margin-left: -200px;z-index: 1000;display: none;padding: 12px 0;text-align: center;color: #fff;background: #2196f3;
    border-radius: 2px;-moz-box-sizing: border-box;-webkit-box-sizing: border-box;-o-box-sizing: border-box;-ms-box-sizing: border-box;box-sizing: border-box;-webkit-transition: all 0.46s ease;
    -moz-transition: all 0.46s ease;-o-transition: all 0.46s ease;transition: all 0.46s ease;
}
.messageShow {top: 6px;z-index: 2000;}

//Body部分
<div class="message"></div>

//JS部分

function messageShow() {

    var w = $('.message');

    w.addClass('messageShow');
}

function messageHide() {

    var w = $('.message');
    w.removeClass('messageShow').removeClass('messageShowNavFix');
    w.html('');
}

function messageOut() {

    var w = $('.message');
    w.css('display', 'none');
}

var t1, t2, t3;
function message(str) {

    var w = $('.message');
    clearTimeout(t1);
    clearTimeout(t2);
    clearTimeout(t3);

    w.html(str);
    w.css('display', 'block');

    t1 = setTimeout("messageShow()", 80);

    t2 = setTimeout("messageHide()", 2500);

    t3 = setTimeout("messageOut()", 3000);
}

//应用部分,如：
$('.btn').click(function(){
message("手机号不能为空，请输入手机号");
   return;
});