在同一页面上出现注册验证错误信息

我目前正在创建一个注册页面并检查错误。我有错误工作正确，但当我报告他们，他们最终在一个新的页面。我想知道我如何得到它不重定向到不同的页面?

我回显出一个div，我认为会出现在表单旁边，但这并没有发生。下面是我的表单和错误验证:

<form action="signup.php" method="post">
                <input type="text" name="First_name" placeholder="First Name" />
                <input type="text" name="Last_name" placeholder="Last Name" />
                <input type="text" name="Email" placeholder="Email Address" />
                <input type="text" name="Email2" placeholder="Comfirm Email Address" />
                <input type="password" name="Password" placeholder="Password" />
                <input type="submit" value="Submit" name="submit"/>
</form>

这是我php文件的一部分。

if (isset($_POST['submit'])) {
$error = array();
$firstname=$_POST['First_name'];
$lastname=$_POST['Last_name'];
$email=$_POST['Email'];
$email2=$_POST['Email2'];
$password=$_POST['Password'];
if (strlen($password) <= 6 and strlen($password) >= 1) {
    if (strlen($password) >= 20) {
        if (strlen($email) >= 1 and strlen($email) <= 55) {
            if ($email == $email2) {
                if (ereg('^[a-zA-Z0-9'-'.]+@[a-zA-Z0-9'-]+'.[a-zA-Z0-9'-'.]+$', $email)) {
                        $sql = "INSERT INTO Users (First_Name, Last_Name, Email, Password) VALUES ('$firstname','$lastname','$email','$password')";
                            echo "Regiration Complete. Check Email for Validation.";
                            exit;
                    } else {
                        $error[] = 'Email is wrong';
                    }
                } else {
                    $error[] = 'Email addresses are not the same';
                }
            } else {
                $error[] = 'Email Address is too long';
            }
        } else {
            $error[] = 'Password is too long';
        }
    } else {
        $error[] = 'Password must be 6 Characters';
    }
}
echo '<div class="errormsgbox"> <ol>';
    foreach ($error as $key => $values) {
        echo '  <li>'.$values.'</li>';
    }
echo '</ol></div>';