Search, desperately if necessary, for some alternative.
Allowing users to enter the full range of HTML and passing them on to other elements on the server side is an invitation to:
- Horribly ill-formatted posts (that will break your XHTML anyway)
- Frustration and anger on your part
or
- Exploitable vulnerabilties (validation notwithstanding) since your spec says "...I need to allow full HTML codes to be entered and passed through to the template.