Frames

Just moved servers and a website I created long time ago now wont display as it uses frames, I know its not common practice to use frameset anymore but its not really worth putting in the time to completely redesign the site are not that important but dont really want to close it is still has lot of info of use to some people.
Site worked perfectly at old hosting, new hosting company cant seem to find out it why it wont display, and say its a developer problem, I think personally I need to add some initial code to the start of index.html file but dont know what, anyone can help ?