提交按钮第一次单击时无法在PhP中使用，但第二次可以使用

Question

<?php include 'header.php';

?>
<div id="body">
<form name="form4" method="get" action="" >
 <table border="1" align="center">
  <tr>
<td colspan="2" align="center">
    <b>Login</b>
</td>
</tr>
<tr>
<td>
  Email : </td>
<td><input type="email" name="txtEmail"></td>
</tr>
<tr>
<td>Passowrd : </td>
<td><input type="password" name="txtPwd"></td>
</tr>

<tr>
<td align="center"> <input name="login" type="submit" id="login" value="login"></td>
<td align="center"><input type="button" name="txtCancel" value="Cancel"/></td>
</tr>
</table>
</form>
</div>
<?php
include('connect.php');
if(isset($_REQUEST['login']))
{
$Email=$_GET['txtEmail'];
$Pwd=$_GET['txtPwd'];
$query="select * from usermaster where EmailId='$Email' and  Password='$Pwd'";
 echo $query;
$result=$conn->query($query);
if ($result->num_rows > 0)
    {
        echo "valid UserName and Password";
        $_SESSION['email']=$Email;// session already started in header.php file
        header("location:user/index.php");
    } 
else 
{
echo "Error: " . $query . "<br>" . $conn->error;
//echo "Invalid UserName and Password";
}

}
?>
 <?php include 'footer.php'; ?>

I have two text boxes 'username' and 'password'. But when I fill the text boxes and click on submit button it is not working and not executing php code.

When I try with empty text-box it executes php code and gives this error - invalid username password.

Answer 1

You haven't filled the action part of your form

A good example:

<form method="get" name="form4" action="<?= $_SERVER['PHP_SELF']; ?>">        
    <!-- Your form here -->
</form>

Since you gave it the PHP tag this should work and redirect your form to the current file.

If you would like to use another php file:

<form method="get" name="form4" action="php_file.php">
    <!-- Your form here -->
</form>

Update

A complete form example. Maybe this will help you out.

<?php
if (isset($_GET)) {
    $username = isset($_GET['username']) ? $_GET['username'] : false;
    $password = isset($_GET['password']) ? $_GET['password'] : false;

    if (false === $useranme || false === $password) {
        die("Not all fields are filled!");
    }
}
?>
<form method="GET" action="<?= $_SERVER['PHP_SELF']; ?>">
    <input type="text" name="username" />
    <input type="password" name="password" />
    <input type="submit" name="login" value="Login" />
</form>

Note:

If this doesnt help you, place the following code at the top of your file:

<?php
error_reporting(E_ALL);
ini_set('display_errors', 'On');
?>

That will turn on error reporting and show errors that might occur. If you have any errors, post them here (edit your question) so we can help you further.

Answer 2

in your form action add # and change method to post

<form name="form4" method="post" action="#" >

and in php

if (isset($_POST['login']))
{
    $email = $_POST['txtEmail'];
    $pwd = $_POST['txtPwd'];

    $query = "select * from usermaster where EmailId='$email' and  Password='$pwd'";

    $result = mysql_query($query);
    $count = count($result);

    if (empty($count) || $count > 1)
    {
        #invalid user
        echo "Invalid username";
    }
    else
    {
        #valid user
        echo "valid UserName and Password";
        //$_SESSION['email'] = $email; // session already started in header.php file
        //header("location:user/index.php")

    }
}