/* Created By:   Yan Yan 
   Date Created: 05/24/2007
   Description:  the javascript functions are used to track user variable.
*/

//get the URL parameter for strParamName, i.e. "www.ccse.com?uv=yahoo"
function getURLParamStr(strParamName){
  var strReturn = "";
  var strHref = window.location.href;
  if ( strHref.indexOf("?") > -1 ){
    var strQueryString = strHref.substr(strHref.indexOf("?")).toLowerCase();
    var aQueryString = strQueryString.split("&");
    for ( var iParam = 0; iParam < aQueryString.length; iParam++ ){
      if ( 
        aQueryString[iParam].indexOf(strParamName.toLowerCase() + "=") > -1 ){
        var aParam = aQueryString[iParam].split("=");
        strReturn = aParam[1];
        break;
      }
    }
  }
  return escape(strReturn);
} 

//get the value for a cookie 
function getCookie(c_name)
{
    if (document.cookie.length>0)
    {
      c_start=document.cookie.indexOf(c_name + "=");
      if (c_start!=-1)
      { 
        c_start=c_start + c_name.length+1 ;
        c_end=document.cookie.indexOf(";",c_start);
        if (c_end==-1) c_end=document.cookie.length;
        return unescape(document.cookie.substring(c_start,c_end));
      } 
    }
    return ""
}

//set a cookie
function setCookie(c_name,value)//,expiredays)
{
    //var exdate=new Date()exdate.setDate(exdate.getDate()+expiredays)
    document.cookie=c_name+ "=" +escape(value);//+
    //((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
}

//Get the user variable. First check the url, next check the cookie.
function getUV()
{
   var strUV = getURLParamStr("uv");
   if(strUV!= "")
   {
        setCookie("uv", strUV);
        return strUV;
   }
        return getCookie("uv");
}