try this
NPC Code:
if (playerchats) {
tokenize #c;
if (tokenscount==2&&strequals(#t(0),/jail)) {
addstring server.jailed,#t(1);
setplayeprop #c, ; }
if (tokenscount==2&&strequals(#t(0),/unjail)) {
if (lindexof(#t(1),server.jailed)>=0) {
deletestring server.jailed,lindexof(#t(1),server.jailed);
} else { say2 #t(1) isn't in jail; }
setplayerprop #c, ;
}
}
thats a pretty simple script, you will have to write a script that will jail the player (should be server side)