function click() {
    if (event.button==2||event.button==3) {
        oncontextmenu='return false';
    }
}

document.onmousedown = click
document.oncontextmenu = new Function("return false;")

function disableselect(e){
    return false
}

function reEnable(){
    return true
}

document.onselectstart=new Function ("return false")

if (window.sidebar){
    document.onmousedown=disableselect
    document.onclick=reEnable
}