// Copyright © 1998-2010 Wulfsoft
// http://www.htmlguard.com/articles/disabling-the-context-menu-in-firefox/
var onlyOnImages = false;

// Detect the browser we have to handle with
var isIE5 = document.all && document.getElementById;  // IE 5 or higher
var isMoz = !isIE5 && document.getElementById;  // Mozilla/Firefox

function cancelContextMenu(e) {
    // Here you can add additional code that is executed when the context menu
    // is blocked. For instance you can use the following code to display a
    // message to the user:
    //alert("Please respect our copyright. Thank you!");
    alert(message)
    if (e && e.stopPropagation)
        e.stopPropagation();

    return false;
}

/* This function is fired every time a user clicks the right mouse button to
open the browser's context menu. */
function onContextMenu(e) {
    // Depending on the "onlyOnImages" variable the context menu is either
    // blocked for the complete page or only for <img> tags.
    if (onlyOnImages && (isIE5 && event.srcElement.tagName == "IMG") || (isMoz && e.target.tagName == "IMG")) {
        return cancelContextMenu(e);}
    else if (onlyOnImages && e.target.tagName == "IMG") {return cancelContextMenu(e);}
    else if (!onlyOnImages) {return cancelContextMenu(e);}
}

if (document.getElementById) {
    // Register event handler
    document.oncontextmenu = onContextMenu;
}