. . . isn't secure. While you may be protecting yourself against some folks, those who actually want to deface your weblog will easily POST anything they want, without going through the JS. The real answer to your problem is to not use a proprietary hosted service, but to set up a weblog on private hosting. If you absolutely MUST have it for free, try awardspace.com; but don't think that any sort of JS input validation is secure.

At least you're not writing user authentication in JS! Oy ve! I've seen people do it, though . . . *grin*

I've got good news, and I've got bad news:
The universe is merely a figment of my imagination.
Now are you ready for the bad news?