js点击复制功能

<a href="/index?ac=ykc_xq&id={$val['kcid']}&yhcode={$val['yhcode']}" οnclick="fuzhi({$val['id']});return false;">复制链接</a>
<input id="shareText_{$val['id']}" style="position: absolute;top: 0;left: 0;opacity: 0;z-index: -10;" value="{$val['mingcheng']}  https://www.xxxx.org/index?ac=aaa&yhcode={$val['yhcode']}">
 input隐藏就不不起作用了

<script type="text/javascript">
    function fuzhi(id) {
        var input = document.getElementById("shareText_"+id);
        input.select();
        document.execCommand("copy");
        // alert("复制成功");
    }
</script>