15. The computer program product of claim 14 wherein the code for previewing the content package file displays the content from the first level and the second level content files in a hierarchical format.
14. The computer program product of claim 13 further comprising: code for fetching the second level content files referred to in the first level content files; code for obtaining content from the second level content files; code for replacing the references to the second level content files with the content from the second level content files to create the combined file.