[Slaktmaster]

if (playerenters) {
this.angle = 0;
this.distance = 2;
timeout = 0.05;
}

if (timeout) {
this.x = x+sin(this.angle)*this.distance;
this.y = y+cos(this.angle)*this.distance;
this.angle+=0.05;
if (this.angle>6.28) {this.angle=0;}
showimg 0,light2.png,this.x,this.y;
changeimgcolor 0,1,1,1,0.8;
changeimgvis 0,2;
timeout = 0.05;
}

note that this is a client-side npc, not to be used with npc server.