Checking Variables to see the highest

[Ascendancy]

Let's say that I have 13 variables, $one through $thirteen. How can I take the 13 variables and compare them all to see which one has the highest value(If all of them are set to number values)?

[Charles]

http://www.php.net/manual/en/function.max.php

[Ascendancy]

Didn't even know about that function, thanks for the help.