If javascript result like...then...

Hi,

I want to change the code, if the result like some strings, then change to another strings,

can someone help me ?


<script language="JavaScript" src="http://www.fishinghk.com/addon/feed2js/feed2js.php?
src=http://rss.weather.gov.hk/rss/WeatherWaingBulletin_uc.xml&num=1&desc=1&utf=y" charset="UTF-8" type="text/javascript"></script>


Many thanks!!