Copy the following code into your HEAD tags.

<SCRIPT LANGUAGE="JavaScript"> /* One Time Popup Script By Website Abstraction (http://www.wsabstract.com) and Java-Scripts.ma.cx (http://www.java-scripts.ma.cx) Over 200+ free scripts here! */ //number of days the cookie should //last (0 will cause it to always pop up) var expDays = 1; //url of the page you want to popup var page = "http://www.codearena.com"; var windowprops = "width=650, height=500, location=yes, toolbar=no, menubar=no, scrollbars=yes, resizable=yes"; function GetCookie (name) { var arg = name + "="; var alen = arg.length; var clen = document.cookie.length; var i = 0; while (i < clen) { var j = i + alen; if (document.cookie.substring(i, j) == arg) return getCookieVal (j); i = document.cookie.indexOf(" ", i) + 1; if (i == 0) break; } return null; } function SetCookie (name, value) { var argv = SetCookie.arguments; var argc = SetCookie.arguments.length; var expires = (argc > 2) ? argv[2] : null; var path = (argc > 3) ? argv[3] : null; var domain = (argc > 4) ? argv[4] : null; var secure = (argc > 5) ? argv[5] : false; document.cookie = name + "=" + escape (value) + ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) + ((path == null) ? "" : ("; path=" + path)) + ((domain == null) ? "" : ("; domain=" + domain)) + ((secure == true) ? "; secure" : ""); } function DeleteCookie (name) { var exp = new Date(); exp.setTime (exp.getTime() - 1); var cval = GetCookie (name); document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString(); } var exp = new Date(); exp.setTime(exp.getTime() + (expDays*24*60*60*1000)); function amt(){ var count = GetCookie('count') if(count == null) { SetCookie('count','1') return 1 } else { var newcount = parseInt(count) + 1; DeleteCookie('count') SetCookie('count',newcount,exp) return count } } function getCookieVal(offset) { var endstr = document.cookie.indexOf (";", offset); if (endstr == -1) endstr = document.cookie.length; return unescape(document.cookie.substring(offset, endstr)); } function checkCount() { var count = GetCookie('count'); if (count == null) { count=1; SetCookie('count', count, exp); window.open(page, "", windowprops); } else { count++; SetCookie('count', count, exp); } } window.onload=checkCount </script>