@MrSnowDropApr 13.2011 — #Inside an "onclick" statement you don't have to start with "javascript:" syntax; besides, it's appropriate to correct your code this way:
@MrSnowDropApr 13.2011 — #I'm not sure to really understand your need...
If you press the "F5" key, a page will refresh independently from the source code; the above script is a shortcut to refresh the page without the need to search and press the function key over the keyboard.
AFAIK, there is no way to clear the cache using JavaScript - that is in the browser settings. The URL above explains the way to refresh the page [I]while skipping the cached content and getting fresh content from the server[/I].