function addHandler(object, event, handler){
	if (typeof object.addEventListener != 'undefined')
		object.addEventListener(event, handler, false);
	else if (typeof object.attachEvent != 'undefined')
		object.attachEvent('on' + event, handler);
	else
		throw "Incompatible browser";
}

function removeHandler(object, event, handler){
if (typeof object.removeEventListener != 'undefined')
	object.removeEventListener(event, handler, false);
else if (typeof object.detachEvent != 'undefined')
	object.detachEvent('on' + event, handler);
else
	throw "Incompatible browser";
}