dereleviate

Hello, I have been finding words linked to an outside site on my webpages. I can not find anything in the source code for these links but they are there in Explorer on windows. They are not there in Navigator or in any browser on my mac. If I reload the pages the links disappear but reappear the next day. I do not find this on any other sites. Does anyone know what is causing this and how to stop it? Keywords I have found linked so far, Travel, Cruise and Tax. Thanks, Dave