/*==============================================================================



    Routines written by John Gardner - 2003 - 2005



    See www.braemoor.co.uk/software for information about more freeware

    available.



================================================================================



Routine to write a session cookie



    Parameters:

        cookieName        Cookie name

        cookieValue       Cookie Value

    

    Return value:

        true              Session cookie written successfullly

        false             Failed - persistent cookies are not enabled



   e.g. if (writeSessionCookie("pans","drizzle") then

           alert ("Session cookie written");

        else

           alert ("Sorry - Session cookies not enabled");

*/



function writeSessionCookie (cookieName, cookieValue) {

  if (testSessionCookie()) {

    document.cookie = escape(cookieName) + "=" + escape(cookieValue) + "; path=/";

    return true;

  }

  else return false;

}



/*==============================================================================



Routine to get the current value of a cookie



    Parameters:

        cookieName        Cookie name

    

    Return value:

        false             Failed - no such cookie

        value             Value of the retrieved cookie



   e.g. if (!getCookieValue("pans") then  {

           cookieValue = getCoookieValue ("pans2);

        }

*/
/*
function get_cookie ( cookie_name )
{
  var results = document.cookie.match ( '(^|;) ?' + cookie_name + '=([^;]*)(;|$)' );

  if ( results )
    return ( unescape ( results[2] ) );
  else
    return null;
}
*/

function getCookieValue (cookieName) {

  var exp = new RegExp (escape(cookieName) + "=([^;]+)");

  if (exp.test (document.cookie + ";")) {

    exp.exec (document.cookie + ";");

    return unescape(RegExp.$1);

  }

  else return false;

}



/*==============================================================================



Routine to see if session cookies are enabled



    Parameters:

        None

    

    Return value:

        true              Session cookies are enabled

        false             Session cookies are not enabled



   e.g. if (testSessionCookie())

           alert ("Session coookies are enabled");

        else

           alert ("Session coookies are not enabled");

*/



function testSessionCookie () {

  document.cookie ="testSessionCookie=Enabled";

  if (getCookieValue ("testSessionCookie")=="Enabled")

    return true 

  else

    return false;

}



/*==============================================================================



Routine to see of persistent cookies are allowed:



    Parameters:

        None

    

    Return value:

        true              Session cookies are enabled

        false             Session cookies are not enabled



   e.g. if (testPersistentCookie()) then

           alert ("Persistent coookies are enabled");

        else

           alert ("Persistent coookies are not enabled");

*/



function testPersistentCookie () {

  writePersistentCookie ("testPersistentCookie", "Enabled", "minutes", 1);

  if (getCookieValue ("testPersistentCookie")=="Enabled")

    return true  

  else 

    return false;

}



/*==============================================================================



Routine to write a persistent cookie



    Parameters:

        CookieName        Cookie name

        CookieValue       Cookie Value

        periodType        "years","months","days","hours", "minutes"

        offset            Number of units specified in periodType

    

    Return value:

        true              Persistent cookie written successfullly

        false             Failed - persistent cookies are not enabled

    

    e.g. writePersistentCookie ("Session", id, "years", 1);

*/       



function writePersistentCookie (CookieName, CookieValue, periodType, offset) {



  var expireDate = new Date ();

  offset = offset / 1;

  

  var myPeriodType = periodType;

  switch (myPeriodType.toLowerCase()) {

    case "years": 

     var year = expireDate.getYear();     

     // Note some browsers give only the years since 1900, and some since 0.

     if (year < 1000) year = year + 1900;     

     expireDate.setYear(year + offset);

     break;

    case "months":

      expireDate.setMonth(expireDate.getMonth() + offset);

      break;

    case "days":

      expireDate.setDate(expireDate.getDate() + offset);

      break;

    case "hours":

      expireDate.setHours(expireDate.getHours() + offset);

      break;

    case "minutes":

      expireDate.setMinutes(expireDate.getMinutes() + offset);

      break;

    default:

      alert ("Invalid periodType parameter for writePersistentCookie()");

      break;

  } 

  

  document.cookie = escape(CookieName ) + "=" + escape(CookieValue) + "; expires=" + expireDate.toGMTString() + "; path=/";

}  



/*==============================================================================



Routine to delete a persistent cookie



    Parameters:

        CookieName        Cookie name

    

    Return value:

        true              Persistent cookie marked for deletion

    

    e.g. deleteCookie ("Session");

*/    



function deleteCookie (cookieName) {



  if (getCookieValue (cookieName)) writePersistentCookie (cookieName,"Pending delete","years", -1);  

  return true;     

}