Toggle Action Cookie Script

2. Obtain the Script

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Introduction

To add the ability to toggle between two actions to your web page you first need to copy the Javascript code into the head section of your page.

// Toggle Action Processing
// copyright 9th January 2007, Stephen Chapman
// permission to use this Javascript on your web page is granted
// provided that all of the below code in this script (including this
// comment) is used without any alteration
function rC(nam) {var tC = document.cookie.split('; '); for (var i = tC.length - 1; i >= 0; i--) {var x = tC[i].split('='); if (nam = x[0]) return unescape(x[1]);} return '0';} function wC(nam,val,expires) { if (!expires) expires = new Date(); expires.setDate(expires.getDate()+1); document.cookie = nam + '=' + escape(val)+ '; expires='+ expires.toGMTString()+ '; path=/';} function thisPage() {var page = location.href.substring(location.href.lastIndexOf('\/')+1); pos = page.indexOf('.');if (pos > -1) {page = page.substr(0,pos);} return page;} function toggle(nam,expires) {var val = rC(nam); if (val=='1') {wC(nam,'0',expires); return false;} wC(nam,'1',expires); return true;}

// example code to call it - you may modify this as required

var expires = 0;
// note that by default the script saves the cookie for one day
// if you wish to keep the cookie for a longer or shorter period then
// set the expires variable to the required expiry date instead of 0.

function start() {
   if (toggle(thisPage(),expires)) {
      // this code runs for even numbered visits
      alert('welcome');
   } else {
      // this code runs for odd numbered visits
      alert('hello');

}
   // other code to run every time once page is loaded goes here
}
window.onload = start;

Copy the above Javascript and save it to an external file. I called mine toggle.js.

We can now link the Javascript into the head of our web page using the following code:

The final step is to replace the alert('welcome'); and alert('hello');statements with whatever processing it is that you want to have performed on alternate visits to the page.

Introduction and Sample | Obtain the Script

Stephen Chapman
JavaScript Guide

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