deletestring?!

[Andy0687]

so i was having trouble with a deletestring npc
what i wanted it to do is when used, would trim back the string by one

so something like
lolhi
would become
lolh

when used

this is what i got

NPC Code:

---

    deletestring client.reg#v(this.id),strlen(#s(client.reg#v(this.  id))-1);

---

it gives me no error in the editor and i asked some other people other possibilies to do this, but nothing has worked so far