eyoucms自定义表单添加验证码

<!-- 验证码开始 --> {eyou:notempty name='$field.IsVertify'} 	<div> 		<input type="text" name="vertify" autocomplete="off" placeholder="图片验证码"/> 		<img {$field.VertifyData} title="看不清？点击更换验证码" style="margin-left: 2px;width: 80px;height: 35px;" /> 		看不清？<a href="javascript:void(0);" id="a_vertify" {$field.VertifyData}>点击更换</a> 	</div> {/eyou:notempty} <!-- 验证码结束 -->