// Sets a Cookie with the given name and value
function BtWriteCookie (piKey, piValue, piDay)
{
var sSubDomain;
var nPos;
var sCookie;
 
	sSubDomain = location.hostname;
	nPos = sSubDomain.indexOf('.');
	if (nPos > 0)
	{
	 sSubDomain = sSubDomain.substring (nPos);
	 sCookie= piKey + '=' + escape(piValue) + ';domain=' + sSubDomain + '; path=/';
	}
	else
	{
	 sCookie= piKey + '=' + escape(piValue) + '; path=/';
	}

    if (piDay != 0)
    {
		var oDate = new Date();
		oDate.setDate(oDate.getDate() + piDay);
		sCookie += "; expires=" + oDate.toGMTString();
    }
    
	document.cookie = sCookie;
}

function BtSetCookie (piKey, piValue)
{
 BtWriteCookie (piKey, piValue, 0);
}	

// Read the value of the specified cookie
function BtReadCookie (piKey)
{
    var dc = document.cookie;
    var prefix = piKey + "=";
    var begin = dc.indexOf("; " + prefix);
    
    if (begin == -1)
    {
        begin = dc.indexOf(prefix);
        if (begin != 0)
           return null;
    }
    else
    {
        begin += 2;
    }
    
    var end = document.cookie.indexOf(";", begin);
    if (end == -1)
    {
        end = dc.length;
    }
    
    return unescape(dc.substring(begin + prefix.length, end));
}

function BtRemoveCookie (piKey)
{
  BtWriteCookie (piKey, "", -100);
}

function ReadQueryString(piKey)
{
  var sUrl = window.document.location.href;
  var nPos, nLen;
  var sValue = "";
  var nKeyLen = piKey.length + 1;
  
  nLen = sUrl.length;
  nPos = sUrl.indexOf(piKey + "=")
  if (nPos > 0)
     sValue = sUrl.substr (nPos+nKeyLen ,nLen-nPos-nKeyLen);

  return sValue ;
}