PHP Login Code with Session creation

The below code is good example of verify the Entered user login credential with the Database valid user dable, if its matching mean create the session and redirect that user to the valid page else ask to enter the valid login credential.

<?php
include("../config.php"); //Know more about config.php
$type=$_POST['type']; //HTML Text Box Value
$uname=$_POST['uname']; //HTML Text Box Value
$pwd=$_POST['pwd'];
$query=mysql_query("SELECT * FROM `adminlogin`"); // else we can directly put the user name and password in query
while($re=mysql_fetch_array($query))
{
if($uname==$re['uname'] && $pwd==$re['pwd'])
{
{
//valid user
session_start();
$_SESSION['admin']=$uname;
$flag=1;
header("location:success.php");
exit;
}
}
else
{ 
$flag=0;
}
}
if($flag==0)
{
include ("index.php");
echo "<center> </BR> <B>"."Invalid User ";
}
?>