function change_lang(lang){ 
	var the_url = window.location.href;
  if(the_url.indexOf("&lang=") > 1){
		the_new_url = the_url.substring(0, the_url.indexOf("&lang="));
	  the_new_url = the_new_url + the_url.substring(the_url.indexOf("lang=")+7, the_url.length);
    the_url = the_new_url;
	}
  if(the_url.indexOf("?") < 1){
  	the_url = the_url + "?lang=" + lang;
  }else{
    the_url = the_url + "&lang=" + lang;    
  }
  window.location.href = the_url
}
  
function getURLParam(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 + "=") > -1 ){
      	var aParam = aQueryString[iParam].split("=");
        strReturn = aParam[1];
        break;
      }
    }
  }
  return strReturn;
}
  
function set_active_tab(){
  if(window.location.href.indexOf("lang=") > 1){
  	the_tab = document.getElementById(getURLParam("lang")+"_tab");
	}else{
		// default to english:
		the_tab = document.getElementById("en_tab");
	}
	the_tab.style.color = '#feb348';
}