function Listener(fp, scope, removing) {
this.fp = fp;
this.scope = scope;
this.removeing = removing;
}
Listener.add = function(oSource, sEvent, fpDest, oScope, bRunOnce) {
if (!oSource[sEvent] || oSource[sEvent] == null || !oSource[sEvent]._listeners) {
oSource[sEvent] = function() { Listener.fire(oSource, sEvent, arguments) };
oSource[sEvent]._listeners = new Array();
}
var idx = this.findForEvent(oSource[sEvent], fpDest, oScope);
if (idx == -1) idx = oSource[sEvent]._listeners.length;
oSource[sEvent]._listeners[idx] = new Listener(fpDest, oScope, bRunOnce);
}
Listener.remove = function(oSource, sEvent, fpDest, oScope) {
var idx = this.findForEvent(oSource[sEvent], fpDest, oScope);
if (idx != -1) {
var iLast = oSource[sEvent]._listeners.length - 1;
oSource[sEvent]._listeners[idx] = oSource[sEvent]._listeners[iLast];
oSource[sEvent]._listeners.length--;
}
}
Listener.findForEvent = function(fpEvent, fpDest, oScope) {
if (fpEvent._listeners) {
for (var i = 0; i < fpEvent._listeners.length; i++) {
if (fpEvent._listeners[i].scope == oScope && fpEvent._listeners[i].fp == fpDest) {
return i;
}
}
}
return -1;
}
Listener.fire = function(oSourceObj, sEvent, args) {
if(oSourceObj&&oSourceObj[sEvent]&&oSourceObj[sEvent]._listeners) { 
var lstnr, fp;
var last = oSourceObj[sEvent]._listeners.length - 1;
for (var i = last; i >= 0; i--) {
lstnr = oSourceObj[sEvent]._listeners[i];
fp = lstnr.fp;
fp.apply(lstnr.scope, args);
if (lstnr.remove) Listener.remove(oSourceObj, sEvent, lstnr.fp, lstnr.scope);
}
}
return(-1)
}
if (!Function.prototype.apply) {
Function.prototype.apply = function(oScope, args) {
var sarg = [];
var rtrn, call;
if (!oScope) oScope = window;
if (!args) args = [];
for (var i = 0; i < args.length; i++) {
sarg[i] = "args["+i+"]";
}
call = "oScope.__applyTemp__(" + sarg.join(",") + ");";
oScope.__applyTemp__ = this;
rtrn = eval(call);
delete oScope.__applyTemp__;
return rtrn;
}
}