code for login page

$myusername=$_POST['txtusername'];
$mypassword=$_POST['txtpassword'];


$sql="SELECT * FROM employ_info WHERE (email = '$myusername') and (password = '$mypassword')";
if($sql){
$result=mysql_query($sql);
$count=mysql_num_rows($result);
if($count == 1)
{ 
session_start(); 
$_SESSION['s_username'] = $myusername; // store session data


header("location:profile.php");
}
 else{
alert ("Username or Password is wrong");
}