左侧表单内容COPY右边框框里面

<from><input type="text" name="s1" id="s1">  <select name="select">
    <option>这边选项的是哪个</option>
    <option>2</option>
    <option>3</option>
  </select>
<input type="button" onclick="copy()" value="copy"> <input type="text" name="s2" id="s2"><select name="select">
    <option>这边就显示哪个</option>
    <option>2</option>
    <option>3</option>
  </select></form>