$().value取值

Question

<script type='text/javascript' src='dwr/interface/saveskin.js'></script>
      <script type='text/javascript' src='dwr/engine.js'></script>
      <script type='text/javascript' src='dwr/util.js'></script>
function kkk(){   saveskin.saveSkin(
     $(userpath).value,$(username).value,2
   );
}
<input type="hidden" name="userpath" id="userpath"  value="<%=userinfo.getUserPath()%>" />
<input type="hidden" name="username" id="username"  value="<%=userinfo.getUid()%>" />
<input type="button" onclick="kkk();" value="aaaaaa" />$(userpath).value,$(username).value这两个为什么取不到值呢？
改成下面这样是可以的
function kkk(){
   saveskin.saveSkin(
     "D:\\turbomail\\accounts\\abc.com\\test","test",2 
   );
}

Answer 1

userpath  username  用引号引起来！

Answer 2

$('userpath').value,$('username').value