function disable_right_click(e)
{
    var event_number = 0;
    if (browserName=="Microsoft"){
        event_number = event.button;}
    else if (browserName=="Netscape"){
		event_number = e.which;}
    if ( event_number==2 || event_number==3 )
        {
        alert ("Die Bilder des Internationalen Baum Archives (IBA) sind urheberrechtlich geschützt.");
        return (false);
        }
    return (true);
}

function check_mousekey ()
{
	var mouse_key = 93;
	if ( browserName == "Microsoft"){
    	var keycode = event.keyCode;
		if ( keycode == mouse_key )
        alert ("Die Bilder des Internationalen Baum Archives (IBA) sind urheberrechtlich geschützt.");
	}
}

function init ()
{
    browserName = navigator.appName.substring ( 0, 9 );
	browserVersion = navigator.appVersion.substring(0,1);
	
	// Version 6 scheint onClick vor onMousedown zu stellen
	if (browserVersion == 5){document.onclick = disable_right_click;}
	else if (browserVersion == 4){document.onmousedown = disable_right_click;}
	
	// keyboard deaktivieren
    if ( browserName == "Microsoft" ){document.onkeydown = check_mousekey;}
    else if ( browserName == "Netscape" && browserVersion != 5){document.captureEvents( Event.MOUSEDOWN );}
}