That is just a warning and it can probably be ignored if everything works.  However I can still probably fix it.  Try changing that line from:
  if (strpos($SessionVal,"<".strtolower($paramName))>=0 && strpos($SessionVal,"</"+strtolower($paramName))>=0)  {
to:
  if (strpos($SessionVal,"<".strtolower($paramName)) !== false && strpos($SessionVal,"</"+strtolower($paramName)) !== false)  {


