帝国CMS二次开发怎么设置会员随机头像

<table width="100%">
    <tr>
        <td valign="top">随机图像：</td>
        <td bgcolor='ffffff'>
            <img src='/e/template/Style/img/1.jpg' id='img2' width="180" height="180" />
        </td>
    </tr>
    <tr>
        <td colspan="2" height="20"></td>
    </tr>
    <tr>
        <td colspan="2"><a class="changeImg" href="javascript:void(0)" onclick="ChangeFace()">换一张</a>
        </td>
    </tr>
    <tr>
        <td colspan="2" height="20"></td>
    </tr>
    <tr>
        <td colspan="2" align="center">
            <button class="editPassword-submit" type="submit" id="faceSubmit">使用头像</button>
        </td></tr>
</table>
<script type="text/javascript">
    function ChangeFace() {
        //x上限，y下限     
        var x = 10;
        var y = 1;
        var rand = parseInt(Math.random() * (x - y + 1) + y);
        var face = '/e/template/Style/img/' + rand + '.jpg';
        $("#img2").attr('src', face);
        $("input[name='userpic']").attr('value', face);
    }
</script>

<input name="userpic" type="text" id="userpic" value="<?=$ecmsfirstpost==1?"":ehtmlspecialchars(stripSlashes($addr[userpic]))?>" size="" style="display:none">
<?=empty($addr[userpic])?"":"<img src='".ehtmlspecialchars(stripSlashes($addr[userpic]))."' border=0 id=img2>"?><br>

<input type="file" name="userpic2file" size="45">
<input name="userpic2" type="text" id="userpic2" value="<?=$ecmsfirstpost==1?"":ehtmlspecialchars(stripSlashes($addr[userpic2]))?>" size="" style="display:none">

<input type='submit' name='Submit' value='上传头像' onclick="bt();">

function bt(){
var txt = $("input[name='userpic2']").val();
$("input[name='userpic']").attr('value',txt);
}