I need help with a marketplace plot claiming system

[master_of_pooms]

This is my current code:

command /mpbuyplot <text>:
usage: /mpbuyplot <id>
trigger:
set {plot} to arg-1
if owner of arg-1 is set:
send "&cSorry, Someone owns that"
else:
if player's balance is greater than 6000:
send "Check 1 complete: You have a sunificant balance"
# I Need help here #
send "&aSucessfully Purchased Plot %arg-1%, you may have to rejoin for changes to take affect"
send "&cMake sure to remove the signs saying that the plot is for sale"
else:
send "&cYou lack funds"

I need help setting the owner of the region (thats what #I need help here# marks)
Ive tried many things, It reloads with no errors. Just doesnt work

 

[Shroob]

Search the docs, remove the balance, use console

 

[master_of_pooms]

?

 

[master_of_pooms]

Ive searched them already
nothing