我没有图片验证码这一栏提交表单报错

{php extract(dr_get_form_post_value('liuyan'))}

<form action="{$post_url}" method="post" id="myform">

{$myfield}

{$diyfield}

{$sysfield}

<input type="submit" id="tj" value="提交" />

<input type="reset" id="cz" value="重置" />

</form>