//alert("please turn on your cookies!");
<!-- hide script from non compliant broswers
// author: Roger W. Davis

//first, calculate an expiration for your temporary test cookie
var oneDay= 1*24*60*60*1000;
var expDate = new Date();
expDate.setTime (expDate.getTime() + oneDay);
var cookieExpires = expDate.toGMTString();
//just for completeness, get the browser information
//document.write("Your browser is: <b>", navigator.appName,"</b><BR>");
//document.write("Version:  <b>",navigator.appVersion,"</b><BR>");
//set your temprorary cookie
document.cookie="verifyCookie=test; expires="+cookieExpires
//check to see if ANY cookies exist, including the one you just set
if (document.cookie.length<=0){
alert("This site requires that cookies be turned on. Thank you!");
}
//now be a good Netizen and clear out the unwanted stuff
document.cookie="verifyCookie=CLEAR; expires=Sun, 09-Nov-97 01:00:00 GMT";
//-->