//Login V1
$sql="SELECT * FROM login WHERE account='$username' && password='$password'";
$result=mysql_query($sql);
$count=mysql_num_rows($result);
if($count==1){
echo "Login Success";
}else{
echo "Login Failed";
}

//Login V2
$result=mysql_query("SELECT * FROM login");
$row = mysql_fetch_array($result);
if($username==$row['account'] && $password==$row['password']){
echo "Login Success";
}else{
echo "Login Failed";
}