i am trying to get electricity effect for my level 34 pants.
what do i do?!

REALLY?LoL you don't know what I mean?
XD not trying to be harsh but you should jet quit where u are man....

NO!.
all i know is that i have to replace the 15 in
upgrade_effect level="15" race="HUMAN" gender="FEMALE" adult="TRUE" equip_type="PANTS
to what my armor level is but then what?

the number "15" on
upgrade_effect level="15" race="HUMAN" gender="FEMALE" adult="TRUE" equip_type="PANTS
don't means the armor lvl but the upgrade lvl. you need to replace the "15" for your pants' upgrade lvl.

You need some basic programming knowledge to do client side edits. If you don't have that I suggest you go learn about it and come back.

Even if you got someone to add the effects for you, what are you going to do every time you upgrade your gear or patch and lose the file? You'll be screwed unless you can get somebody to make it again, which can get incredibly annoying for everybody involved.

u can upgrade the new gear to it ^^

But you can't upgrade to +6 from +5 if you don't know how to change the aura from +5 to +6.

but u can upgrade it to the lvl of the mod ^^

You already said that, so to make the same point again, you can't upgrade beyond the level of the mod.

u dont get my point
when in the mod u did for +2 pants
and u bought new armour then when u upgrade to +2 the mod works again on it