function proctect_message(e) {
	if (!e) e = window.event;
	if ((e.type && e.type == "contextmenu") || (e.button && e.button == 2) || (e.which && e.which == 3)) {
		msg  = "Die Bilder dieser Website unterliegen dem Copyright.";
		setTimeout("alert( msg )", 500);
		return false;
	}
}

function protect_images() { 
	if( document.images ) { 
		for( i=0; i<document.images.length; i++ ) {
			var objImg = document.images[i];
			objImg.oncontextmenu = proctect_message;
			if (!objImg.oncontextmenu)
				objImg.onmousedown = proctect_message;
		}
	}
}
protect_images();