在评论提交前,增加一个必须点击的checkbox确认框,增加二次验证,防止机器人自动发布。
1、方法:只需在提交按钮前再增加一个类型为checkboxinput标签,然后定义 required 属性。
2、美化:一个光秃秃的复选框是不是显得有些丑陋?可以借助css3把按钮美化一下,如类似iPhone开关的风格。
效果(点击试试):

html部分:

<p title="提交评论前请先确认"><input type="checkbox" value="checkbox" id="checkbox_1" class="checkbox_sub" required="required" /><label for="checkbox_1"></label></p>

CSS部分

/*checkbox*/
.checkbox_sub{
    display: none;
}

.checkbox_sub + label {
    background-color: #bdbdbd;
    padding: 9px;
    border-radius: 50px;
    display: inline-block;
    position: relative;
    margin-right: 30px;
    -webkit-transition: all 0.1s ease-in;
    transition: all 0.1s ease-in;
    width: 40px;
    height: 15px;
}

.checkbox_sub  + label:after {
    content: ' ';
    position: absolute;
    top: 0;
    -webkit-transition: box-shadow 0.1s ease-in;
    transition: box-shadow 0.1s ease-in;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 100px;
    box-shadow: inset 0 0 0 0 #eee, 0 0 1px rgba(0,0,0,0.4);
}

.checkbox_sub  + label:before {
    content: ' ';
    position: absolute;
    background: white;
    top: 1px;
    left: 1px;
    z-index: 999999;
    width: 31px;
    -webkit-transition: all 0.1s ease-in;
    transition: all 0.1s ease-in;
    height: 31px;
    border-radius: 100px;
    box-shadow: 0 3px 1px rgba(0,0,0,0.05), 0 0px 1px rgba(0,0,0,0.3);
}

.checkbox_sub:active + label:after {
    box-shadow: inset 0 0 0 20px #eee, 0 0 1px #eee;
}

.checkbox_sub:active + label:before {
    width: 37px;
}

.checkbox_sub:checked:active + label:before {
    width: 37px;
    left: 20px;
}

.checkbox_sub  + label:active {
    box-shadow: 0 1px 2px rgba(0,0,0,0.05), inset 0px 1px 3px rgba(0,0,0,0.1);
}

.checkbox_sub:checked + label:before {
    content: ' ';
    position: absolute;
    left: 26px;
    border-radius: 100px;
}

.checkbox_sub:checked + label:after {
    content: ' ';
    font-size: 1.5em;
    position: absolute;
    background: #4cda60;
    box-shadow: 0 0 1px #4cda60;
}

参考资料:
1、W3School:HTML 5 input required 属性
2、使用CSS3美化复选框checkbox