$result = mysql_query("SELECT * FROM login WHERE username='$user' AND password='$pass'");

 if(!$result)
 {
 echo "Error encountered running query.";
 }

 if($result)
	{
	if(mysql_num_rows($result)==0)
		{
		echo "The information provided is incorrect.";
		}
	else
		{
		echo "You have successfully logged in.";
		}
	}