JavaScript change conflicts -How can we force the new update

Respected community members,

          This is for Iframe ASP.NET Application javascript for CRM 4.0. we have issue with previous javascript conflicts. How can we force users browser to reload the component for first time to pick up the latest javascript and other resources??

if we tell users to delete the browsing history and refresh everything , it works. how can we force only first time??

Thanks,

Nick