// Message for the alert box
var message = "Copyright © You do not have permission to copy these images. Please e-mail us and ask for the pictures you want ";

/**
 * Disables right click on an image.
 * 
 * @param {Object} e
 */
function disable_right_click(e){
    var browser = navigator.appName.substring(0, 9);
    var event_number = 0;
	
    if (browser == "Microsoft") {
		event_number = event.button;
	}
	else if (browser == "Netscape") {
		event_number = e.which;
	}
	
    if (event_number == 2 || event_number == 3) {
        alert(message);
        return (false);
    }
    
    return (true);
}

function trap_images_mouse_events(){
    if (document.images) {
        for (var pic = 0; pic < document.images.length; pic++) 
            document.images[pic].onmousedown = disable_right_click;
    }
}

window.onload = trap_images_mouse_events;