<?php

mysql_connect("localhost","root","")
or DIE('Connection to host is failed, perhaps the service is down!');
mysql_select_db("online_manager") or DIE('Database name is not available!');

if(isset ($_POST["username"]) )
{
$user = $_POST["username"];
}

if(isset ( $_POST["userpass"] ) )
{
$pass = $_POST["userpass"];
}
//echo "$pass";

//you used == instead of = in your query
$usertest = mysql_query("select * from user_information where username = '$user' && password = '$pass' ");

$user= mysql_num_rows($usertest);
//echo "$user";
if($user>0)
{
//echo "$usertest";
//$query = mysql_query("select * from user_information where username = '$user' and password ='$pass'");

echo "$query";
while($row = mysql_fetch_array($usertest))
{

echo $row['name'];
echo $row['email'];
echo $row['address'];

}

}
else {

echo "Invalid Username or Password<br>Try again with correct one!";
include_once("index.html");

}
?>