a标签提交表单的三种写法:
<form name ="form-name" id="form-id" method="post" action="url"></form>
<!--对应name-->
<a href=javascript:document.form-name.submit();"> 提交 </a>
<a href="javascript:;" onclick="javascript:document.form-name.submit();> 提交 </a>
<!--对应id-->
<a href="#" onclick="document.getElementById('form-id').submit();return false> 提交 </a>