/* begin: fundamental functions */
function getURLParam(strParamName){
  var strReturn = "";
  var strHref = window.location.href;
  if ( strHref.indexOf("?") > -1 ){
    var strQueryString = strHref.substr(strHref.indexOf("?"));
    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;
}
/* end: fundamental functions */

/* begin: swap image functions */
function swapImage(thisImg, srcURL){
  thisImg.src = srcURL;
}
/* end: swap image functions */