form 값 iframe 으로 넘기기

<script language="javascript">
 function a() {
  frm.method ="post";
  frm.action = "b.jsp";
  frm.target = "a";
  frm.submit();
 
 }
< /script>
< form name="frm">
 <input type="text" class="box05"  value="" size="18" maxlength=20 name="Contents">
 <a href="javascript:a()">click</a>
 <br />
 <br />

</form>
< iframe frameborder="1" width="540"  src="a.jsp" name="a" scrolling="no" frameborder="0" width="645" height="320"></iframe>