Forums Scripts & Popups if statement

Hello im trying to do something by using on join. What im trying to do is when someone joins my chan if there ip is all number i want it to try and dns that ip and write it to like hosts/<resolved ip>
I got the writing down but i cant seem to figure out on how to make a if statement go if its all numbers only i seen a letters and numbers but thats not what i want can any help?

how about:

on *:join:#channel: {
if (*.*.*.* iswm $address) { dns $nick }
}

Would that work?? *shrugs sholders - no clue - never tried it*

Nope i dont think that will work i tried it anyhow and no go =\

$longip(<input>) returns an integer number when <input> is an IP address, otherwise it returns $null.

thanks man i never delt with ips so i didnt know heh thank u