Drain SP after successfully "itemskill" script

[Timokha]

Hello All,

I have Charge Arrow Scroll, which calls skill "Charge Arrow".

It costs 12 SP to use this scroll.

The questions is:

Is there any way to consume SP only after successfully use of this scroll?

Currently it consumes SP immediately after using the scroll, even if the skill was not used or failed.

Name: "Charge Arrow Scroll"
Type: "IT_DELAYCONSUME" 

Script: <" itemskill AC_CHARGEARROW,1,ISF_CHECKCONDITIONS | ISF_INSTANTCAST; Sp = Sp - 12; ">

Highly appreciate your help.