<form action="">

      <input type="text" class="share-input"  value="http://www.youtube.com" id="copy-content"/>

      <button class="copy-button" type="button" onclick="copyContent();"> 复制 </button>

</form>

<script type="text/javascript">

     /*Copy function implementation */

        function copyContent(){

        var copyobject=document.getElementById("copy-content");

        copyobject.select();

        document.execCommand("Copy");

        alert("已复制成功哦~");

    };

</script>