If you wanna use GET parameters from URL try this
<?php
include "config.php";
session_start();
$email = $_SESSION['email'];
$acc = $_GET['account'];
$amt = $_GET['amount'];
$query = "update account set balance = balance + $amt where acc_no = '$acc'";
mysql_query($query);
$query = "update account set balance = balance - $amt where email = '$email'";
mysql_query($query);
header('Location: kclick.html');
?>