Help: Updating multiple rows in a table

I have this code, I want it to increase the 'users' hp by 5 while keeping their hp below 'maxhp';

Currently it doesn't work, can anyone fix the code below or give me a completely different way to do it?

mysql_query("UPDATE Zombie SET `Hp` = `Hp` + '5'");

$result = mysql_query("SELECT * FROM `Zombie`");

while($row = mysql_fetch_array($result)) {
if ($row['Hp'] >= $row['Maxhp']) {
$row['Hp'] = $row['Maxhp'];
}
$test = $row['Hp'];
echo $row['Maxhp'];
mysql_query("UPDATE Zombie SET `Hp` = '$test'");
}

I don't mind how -as long as it works,

Thanks alot,

James

 

UPDATE Zombie SET Hp = if(Hp + 5 > maxhp, maxhp, Hp + 5)

Code (markup):

Above query considers maxhp as another column in table, if it is not the case, replace it with php variable and its done

 

use link this
"UPDATE Zombie SET Hp = if(Hp + 5 > maxhp, maxhp, Hp + 5)"

 

Thanks Working now.