do you want to load content into the main body part without reloading
the whole page?
does you page use frames to display different parts (header, left menu,
main body) or do you load them into DIVs?
which version of CF are you on? (important since cf8 has buit-in ajax ui
components you can use to change content of parts of page without
reloading whole page, and on prev versions you will have to use some js