Percentage Symbol (%) on post

Hi!

Something are happening on my code, it worked for a while and now stopped.

I have some normal fields in a normal form with a normal button, the button have a value "btSend"...
So in my controller i check:

Code:

if($this->input->post('btId')){
//die("here");
}

The problem is, when i submit texts, numbers and other stuff the form work, but when i write something like "this thing have 20% something" in one of my fields the form seems to not submit... thatss really strange for me, someone can help me please?

(Sorry about my bad english)

Cheers!