表单中多个按钮 怎么实现？

html 页面中的代码.<body>
<form id="form1" name="form1" method="post" action="Rg_1.php">
  <table width="1094" border="1">
    <tr>
      <td width="386" height="104">&nbsp;</td>
      <td width="82">&nbsp;</td>
      <td width="168"><span class="STYLE1">注册信息</span></td>
      <td width="211">&nbsp;</td>
      <td width="213">&nbsp;</td>
    </tr>
    <tr>
      <td height="27">&nbsp;</td>
      <td>用户名：</td>
      <td><input name="txt_user" type="text" id="txt_user" /></td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td height="26">&nbsp;</td>
      <td>密 码：</td>
      <td><input name="txt_password1" type="password" id="txt_password1" /></td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td height="27">&nbsp;</td>
      <td>确认密码：</td>
      <td><input name="txt_password2" type="password" id="txt_password2" /></td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td height="29">&nbsp;</td>
      <td>电 话：</td>
      <td><input name="txt_tel" type="text" id="txt_tel" /></td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td height="31">&nbsp;</td>
      <td>Email:</td>
      <td><input name="txt_email" type="text" id="txt_email" /></td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td height="42">&nbsp;</td>
      <td><label>
      <div align="right">
        <input type="submit" name="Submit" value="提  交" />
      </div>
      </label></td>
      <td><label>
        &nbsp; &nbsp; &nbsp;
        <input type="submit" name="Submit2" value="取  消" />
      </label></td>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
    </tr>
  </table>
</form>
</body>
</html>该界面调用"Rg_1.php"，我在"Rg_1.php"写的事件，它直接调用第一个"提 交"按钮。
我想在"Rg_1.php"页面的中事件能分别 调用"提 交" 和 "取 消"按钮?请问怎么来实现?