This command will start a new execution thread in a specified NPC object at the
specified label. The execution of the script running this command will not stop.
No parameters may be passed with a doevent call.

The script of the NPC object invoked in this manner will run as if it's been
invoked by the RID that was active in the script that issued a 'doevent'.

place,100,100,1%TAB%script%TAB%NPC%TAB%53,{
mes "This is what you will see when you click me";
close;
OnLabel:
mes "This is what you will see if the doevent is activated";
close;
}

....

doevent "NPC::OnLabel";