php做网页登陆页面，传递数据，变量无效，求解

php总共设置了三个变量，判定时发现只有$select有效，其他两个无效，这是怎么回事呀？
求能手回答，赶任务，急
帮个忙，改改，不胜感激
登陆界面代码：

<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style type="text/css">
<!--
.STYLE5 {font-size: 36px}
body {
background-image: url();
}
.STYLE6 {font-size: 18px}
-->
</style>
</head><body>
<table width="900" height="541" border="1" align="center">
  <tr>
    <td height="535" valign="top" bgcolor="#FFFFFF"><table width="900" height="106" border="1">
      <tr>
        <td width="210" height="100" valign="middle"><span class="STYLE5"><img src="20002.gif" width="209" height="107" /></span></td>
        <td width="674" valign="middle"><span class="STYLE5">西南民族大学</span></td>
      </tr>
    </table>
      <table width="900" border="1">
        <tr>
          <td align="center"><span class="STYLE5">实验教学管理系统</span></td>
        </tr>
      </table>
      <table width="900" height="231" border="1">
        <tr>
          <td width="442" rowspan="4">&nbsp;</td>
          <td width="442"><span class="STYLE6">用户登录</span></td>
        </tr>
        <tr>
          <td><form id="form1" name="form1" method="post" action="XXX.php">
            用户
            <label>
              <input type="text" name="textfield" />
              </label>
          </form>
          </td>
        </tr>
        <tr>
          <td height="58"><form id="form2" name="form2" method="post" action="XXX.php">
            密码
            <label>
              <input type="password" name="textfield2" />
              </label>
          </form>
          </td>
        </tr>
        <tr>
          <td height="55" align="right" valign="top"><form id="form3" name="form3" method="post" action="XXX.php">
            <label>
            <select name="select">
                <option value="a">用户类型</option>
                <option value="b">教师</option>
                <option value="c">学生</option>
              </select>
            </label>
            <label>
             <input type="submit" name="Submit" value="登录" />
            </label>
          </form>
          </td>
        </tr>
      </table>
    </td> 
  </tr>
</table>
<p>&nbsp;</p>
<p>&nbsp;</p>
</body>
</html>
php检测代码：
<?php@$textfield=$_POST['textfield'];
@$textfield2=$_POST['textfield2'];
@$select=$_POST['select'];
if(（$textfield=="a")&&($textfield2=="123")&&($select=="b")) //输入a,123,选教师无效，去掉任意        
echo "<p>fffffff</p>";                                 //条件，输入任意数据，发现($select=="b")是有效的，
else                                                        //其他两个语句无用，必为假。 
header("Location: http://localhost/phpmyadmin/Documentation.html");
exit;
?>PHP登陆界面问题

解决方案 »

  1.   

    一个form就ok了， 把第一个form留着，其他的都删掉就行了就是这样
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
    <title>无标题文档</title>
    <style type="text/css">
    <!--
    .STYLE5 {font-size: 36px}
    body {
    background-image: url();
    }
    .STYLE6 {font-size: 18px}
    -->
    </style>
    </head><body>
    <table width="900" height="541" border="1" align="center">
      <tr>
        <td height="535" valign="top" bgcolor="#FFFFFF"><table width="900" height="106" border="1">
          <tr>
            <td width="210" height="100" valign="middle"><span class="STYLE5"><img src="20002.gif" width="209" height="107" /></span></td>
            <td width="674" valign="middle"><span class="STYLE5">西南民族大学</span></td>
          </tr>
        </table>
          <table width="900" border="1">
            <tr>
              <td align="center"><span class="STYLE5">实验教学管理系统</span></td>
            </tr>
          </table>
          <table width="900" height="231" border="1">
            <tr>
              <td width="442" rowspan="4">&nbsp;</td>
              <td width="442"><span class="STYLE6">用户登录</span></td>
            </tr>
            <tr>
              <td><form id="form1" name="form1" method="post" action="XXX.php">
                用户
                <label>
                  <input type="text" name="textfield" />
                  </label>
              </td>
            </tr>
            <tr>
              <td height="58">
                密码
                <label>
                  <input type="password" name="textfield2" />
                  </label>
              </td>
            </tr>
            <tr>
              <td height="55" align="right" valign="top">
                <label>
                <select name="select">
                    <option value="a">用户类型</option>
                    <option value="b">教师</option>
                    <option value="c">学生</option>
                  </select>
                </label>
                <label>
                 <input type="submit" name="Submit" value="登录" />
                </label>
              </form>
              </td>
            </tr>
          </table>
        </td> 
      </tr>
    </table>
    <p>&nbsp;</p>
    <p>&nbsp;</p>
    </body>
    </html>
      

  2.   

    你要逆天了，一个文本框一个表单，你直接把表单放在table外层就可，只需要一个表单的。