PHP - Rotation Conflicts Among Web Browsers

I'm creating a learning tool where people can paste in information and learn about random subjects.   Ideally for a desktop view eg. widescreen, a browser/search engine is on the left, and the interface is on the right.   So I need to embed a browser, I have tried to embed Google but I think, obviously, that they do not permit that.   I have seen possible alternatives like Chromium or Mozilla not firefox, something else "Gecko?"   Anyway, aside from not knowing what a browser is... for example how else can you access a website without a browser, SSH right? But it's about parsing / interpreting the languages correctly...   So what options do I have? Or should I just optimize the website to be used split screen with a browser in a separate tab? (Currently what I'm doing).

I have a Create new account page. The form is in page named Register.php and once user submit it, it will go to Confirm.php, where it validates the field if everything is correct shows the " Account Created " Message.

In Chrome. The error message is shown in Register.php and once all fields are filled then only will show confirm.php. But in Mozilla, it goes to Confirm.php and shows a blank page.

My code for Register.php is :

Code: [Select]
<div class="signup_form">
<form action="confirm.php" method="post" >

<?php 
    session_start();
    if(isset($_SESSION['error']))
    {
        echo '<p>'.$_SESSION['error']['username'].'</p>';
        echo '<p>'.$_SESSION['error']['email'].'</p>';
        echo '<p>'.$_SESSION['error']['password'].'</p>';
        unset($_SESSION['error']);
    }
?>
<p>
<font size="3" face="arial" color="gray"> <label for="username"><b> UserName*</b> </label> </font>
<input name="username" type="text" id="username" input style="height:33px" size = "50" size="30"/>

</p>
<p>
<font size="3" face="arial" color="gray"> <label for="email"><b> E-mail Address*</b> </label> </font>
<input name="email" type="text" id="email"  input style="height:33px" size = "50" size="30"/>
</p>


<p>
<font size="3" face="arial" color="gray"> <label for="password"><b> Password*</b> </label> </font>
<input name="password" type="password" id="password"   input style="height:33px" size = "50" size="30"/>
    </p> 
<p>
<input name="submit" type="image" src="images/submit.gif" value="submit"/>    </p>
</form>

</div>

and for Confirm.php code is :



Code: [Select]
<?php
    session_start();
    include('configdb.php');

    if(isset($_POST['submit']))
    {
        if($_POST['username'] == '')
        {

            $_SESSION['error']['username'] = "User Name is required.";
        }
        if($_POST['email'] == '')
        {
            $_SESSION['error']['email'] = "E-mail is required.";
        }
            else
            {
                if(preg_match("/^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/", $_POST['email']))
                {
                    $email= $_POST['email'];
                    $sql1 = "SELECT * FROM user WHERE email = '$email'";
                    $result1 = mysqli_query($mysqli,$sql1) or die(mysqli_error($mysqli));
                    if (mysqli_num_rows($result1) > 0) {
                        $_SESSION['error']['email'] = "This Email is already used.";
                    }
                }
                else
                {
                $_SESSION['error']['email'] = "Your email is not valid.";
                }
            }
        if($_POST['password'] == '')
        {
            $_SESSION['error']['password'] = "Password is required.";
        }

        if(isset($_SESSION['error']))
        {
            header("Location: register.php");
            exit;
        }
        else
        {
            $username = $_POST['username'];
            $email = $_POST['email'];
            $password = $_POST['password'];

            $sql2 = "INSERT INTO users (username, email, password) VALUES ('$username', '$email', '$password')";
            $result2 = mysqli_query($mysqli,$sql2) or die(mysqli_error());

            if($result2)
            {

            echo '<div>Your account is now active. You may now <a href="login.php">Log in</a></div>';  

We are trying to capture customer details & redirecting the customer to payment gateway page and, after succesful transaction from payment gateway we are facing a problem for different browsers.

Ideally after successful transaction the page should redirect to order confirmation page but it is redirecting to our cart page.In IE7 it is working fine but in mozilla firefox it is redireting to cart page.On analyzing we found that session is not persisting in firefox.
Please help we have stuck here  Suggest something if you have faced similar issue with different browsers.