未捕獲typeerror：無法設置未定義的財產「行動」

Question

我正在嘗試做一個登錄，但是接收「未捕獲的typeerror：無法設置屬性'行動'的readrecord（）函數中的第一行未定義」錯誤，不知道如何解決它。

<script> 
    function readrecord() { 
    document.main.action = "Login.php"; 
    document.getElementById("op").value = "check"; 
    document.main.submit(); 
} 

function Userdontexist() { 
    alert("Username or Password is wrong"); 
} 

function submitForm() { 
    Traveler_Username = document.getElementById('Traveler_Username').value; 
    Password = document.getElementById('Password').value; 

     if (Traveler_Username == "" || Password == "") { 
      alert("Need to fill al the fields"); 
      return; 
     } else { 
     readrecord(); 
}} 
</script> 

<?php 
include 'DB_connection.php'; 
    if (isset($_REQUEST["op"])) $op = $_REQUEST["op"]; else $op = ""; 
    if (isset($_REQUEST["Traveler_Username"])) $Traveler_Username = $_REQUEST["Traveler_Username"]; 
    if (isset($_REQUEST["Password"])) $Password = $_REQUEST["Password"]; 

if ($op=="check") { 
    $query = "select * from users where Traveler_Username =".$Traveler_Username; 
     $result = mysql_query($query) or die('Query failed: ' . mysql_error()); 
     if (mysql_num_rows($result) == 0){ 
      alert("User do not exist"); 
      $Traveler_Username = ""; 
      $Password = ""; 
      header("Location: reg.php"); 
      exit; 
     } else { 
       $query = "select Password from users where Traveler_Username =".$Traveler_Username; 
       $result = mysql_query($query) or die('Query failed: ' . mysql_error()); 
       $row = mysql_fetch_array($result); 
       $db_pass = $row["Password"]; 
       if ($Password == $db_pass){ 
        $Traveler_Username = $row['Traveler_Username'] ; 
        $Password = $row['Password'] ; 
        } else { 
          echo '<script> Userdontexist(); </script>'; 
        } 
      } // end else 
} // end if 

?> 
       <tr> 
       <td style="width: 95px;">Username</td> 
       <td dir="rtl" style=" text-align: center; width: 195px;"> 
       <form method="post" target="_blank"> 
       <input id="Traveler_Username" type="text" dir="rtl" size="10" /> 
        </form> 
       </td> 
       <td>&nbsp;</td> 
      </tr> 

      <tr> 
       <td></td> 
       <td class="he_shadow" style="text-align: center; width: 70px;">&nbsp;</td> 
       <td style="width: 95px;">Password</td> 
       <td dir="rtl" style=" text-align: center; width: 195px;"> 
       <form method="post" target="_blank">     
        <input id="Password" name="Password" type="password" dir="rtl" size="10" /> 
        </form> 
       </td> 
       <td></td> 
      </tr> 

      <tr> 
       <td rowspan="2">&nbsp;</td> 
       <td style="text-align: center; width: 70px;" rowspan="2"> 
       &nbsp;</td> 
       <td style="width: 95px" rowspan="2"> 
       <form method="post" target="_blank"> 
       <input name="Submit1" type="submit" value="login" onclick="readrecord()" style="width: 43px" /> 
       </form></td> 
       <td style="text-align: center; border-bottom-color: #FF9900; width: 195px; height: 30px;"> 
       <input name="Reset1" type="reset" value="clear data" /></td> 
       <td rowspan="2">&nbsp;</td> 
      </tr> 
      <tr> 
       <td style="text-align: center; border-bottom-color: #FF9900; width: 195px;"> 
       &nbsp;</td> 
      </tr> 
      <tr> 
       <td>&nbsp;</td> 
       <td style="text-align: center; width: 70px;"> 
       &nbsp;</td> 
       <td style="width: 95px"> 
       &nbsp;</td> 
       <td style="text-align: center; border-bottom-color: #FF9900; width: 195px;"> 
       &nbsp;</td> 
       <td>&nbsp;</td> 
      </tr> 

</div> 

我需要在代碼中更改什麼？

Answer 1

的問題得到了解決，我不得不改變爲形式的名稱：<form name = "main">

謝謝Barmar。