function ggbOnInit() {[br]ggbApplet.registerAddListener("comprobar");[br]}[br][br]function comprobar(obj) {[br]if (ggbApplet.getObjectType(obj) == "point") {[br][br]ggbApplet.evalCommand([br]"l1=Prove(Distance(A," + obj + ")==Distance(A,B))"[br]);[br][br]ggbApplet.evalCommand([br]"l2=Prove(Distance(B," + obj + ")==Distance(A,B))"[br]);[br][br]var r1 = ggbApplet.getValue("l1");[br]var r2 = ggbApplet.getValue("l2");[br][br]if (r1 == 1 && r2 == 1) {[br]ggbApplet.setValue("vf", 1);[br]} else {[br]ggbApplet.setValue("vf", 0);[br]}[br]}[br]}