function addListener(element, event, listener, bubble) {
    if(element.addEventListener) {
        if(typeof bubble == 'undefined') bubble = false
        element.addEventListener(event, listener, bubble)
    } else if(this.attachEvent) {
        element.attachEvent('on'+event, listener)
    }
}

function removeListener(element, event, listener, bubble) {
    if(element.removeEventListener) {
        if(typeof bubble == 'undefined') bubble = false
        element.removeEventListener(event, listener, bubble)
    } else if(this.detachEvent) {
        element.detachEvent('on'+event, listener)
    }
}