Login validataion in PHP

<?php
include"connect.php";
$un=$_POST['txtuname'];
$up=$_POST['txtpass'];
//echo "$un</br>$up</br>";


$res=pg_query($con,"select count(*) from Users where uname='$un' and upass='$up'");

$r=pg_fetch_array($res);
if($r[0]==1)
{
session_start();
$_SESSION['unm']=$un;
$_SESSION['ups']=$up;

 echo "<script type='text/javascript'>";
                echo "if(confirm('Login Successfully'))document.location='home.html';else document.location='home.html';";
                echo "</script>";

}
else
{

 echo "<script type='text/javascript'>";
                echo "if(confirm('Username or password doesnot match'))document.location='home.html';else document.location='home.html';";
                echo "</script>";

}


?>