DdedeCMS织梦自定义表单添加验证码判断

<input name="validate" type="text" id="vdcode" style="text-transform:uppercase;" size="8"/> 

<img id="vdimgck" class="yzmimg" align="absmiddle" onClick="this.src=this.src+'?'" style="cursor: pointer;" alt="看不清？点击更换" src="../include/vdimgck.php"/> 

<a href="javascript:vide(-1);" onClick="changeAuthCode();">看不清？ </a>

<script type="text/javascript"> 

$ = jQuery; 

function changeAuthCode() { 

var num = new Date().getTime(); 

var rand = Math.round(Math.random() * 10000); 

num = num + rand; 

$('#ver_code').css('visibility','visible'); 

if ($("#vdimgck")[0]) { 

$("#vdimgck")[0].src = "../include/vdimgck.php?tag=" + num; 

} 

return false; 

} 

</script>

$fieldarr = explode(';', $dede_fields);

//新增验证码

if(!empty($dede_fields))

    { 

        $validate = empty($validate) ? '' : strtolower(trim($validate));            

        $svali = strtolower(GetCkVdValue());

        if(($validate=='' || $validate != $svali) && preg_match("/6/",$safe_gdopen)){ 

            ResetVdValue(); 

            ShowMsg('验证码不正确!',$dede_add,0,1000); 

            echo '<script language="javascript">history.go(-1);</script>';

        } 

    }