/* This file contains cookie functions. */
/* File Functions:
   1. setCookie - writes cookie
   2. getCookie - gets value of cookie
   3. removeCookie - deletes a cookie
   4. detectCookies - checks if cookies are enabled
*/

function setCookie(cookieName, cookieValue, expireDays)
   {
   /* Pass in three strings - the name of the cookie, the value, and the number of days until expiration. 
   Pass in a "" empty string for expireDays to set a session cookie (no expires date). 
   Pass in any other date for expire as a number of days to be added totoday's date. */
   
   var expires = "";
   var re = /^\d+$/;
   
   /* make sure expireDays is a number */
   if (expireDays != "" && re.test(expireDays))
      {
      expires = new Date();
      expires.setDate(expires.getDate() + expireDays);
      expires = expires.toGMTString();
      }
   document.cookie = cookieName+"="+cookieValue+";PATH=/;expires="+expires;
  	alert("Current page has been bookmarked")
   }

function removeCookie (cookieName)
   {
   /* Pass in the name of the cookie as a string and it will be removed. */
   expires = new Date();
   expires.setDate(expires.getDate() - 5)
   document.cookie = cookieName + "= ;expires="+expires.toGMTString();
   }

function getCookie (cookieName)
   {
   cookieValue = ""
   if (document.cookie.indexOf(cookieName) == -1)
      {
      /* there is no cookie by this name for this user */
      return cookieValue;
      }
   else
      {
      /* get the beginning index of the cookie by looking for the cookie name */
      cookieStart = document.cookie.indexOf(cookieName);
      /* get the beginning index of the cookie value by looking for the equal sign after the name */
      cookieValStart = (document.cookie.indexOf("=", cookieStart) + 1);
      /* get the end index of the cookie value by looking for the semi-colon after the value */
      cookieValEnd = document.cookie.indexOf(";", cookieStart);
      /* if no semi-colon, then use the whole length */
      if (cookieValEnd == -1)
         {
         cookieValEnd = document.cookie.length
         }
      /* use substring to get the text between the two indices and that is the value of the cookie */
      cookieValue = document.cookie.substring(cookieValStart, cookieValEnd);
      return cookieValue;
      }
   }

function detectCookies()
   {
   /* function returns true if cookies are enables, false if not */
   setCookie("test", "test", "");
   tmp = getCookie("test")
   if (tmp != "test")
      {
      return false;
      }
   else
      {
      return true;
      }
   }