var mymessage = "© Institut Charles Quentin \n1 rue Sabatier\n60350 Pierrefonds\nTél : 03 44 42 80 40 - Fax 03 44 42 07 01\nEmail : pierrefonds@cneap.fr"; 
function rtclickcheck(keyp){
if (navigator.appName == "Netscape" && keyp.which == 3) {
alert(mymessage);
return false;
}
if (navigator.appVersion.indexOf("MSIE") != -1 && event.button == 2) {
alert(mymessage);
return false;
}
}
document.onmousedown = rtclickcheck