Fill in textarea within <noscripts> tags with python mechanize

I'm having a problem with mechanize registering a text area field from within a tag.

Example URL: http://www.gegononta.gr/register.php

Code:

mech = mechanize.Browser()
url = "http://www.gegononta.gr/register.php"
response = mech.open(url)

mech.select_form(nr=1)
mech.form.set_all_readonly(False)

print mech.form

Output:

<POST http://www.gegononta.gr/register.php application/x-www-form-urlencoded
<TextControl(reg_username=)>
<IgnoreControl(reg-checkbutton1=<None>)>
<TextControl(reg_email=)>
<IgnoreControl(reg-checkbutton2=<None>)>
<Pa开发者_如何学PythonsswordControl(reg_password=)>
<PasswordControl(reg_password2=)>
<HiddenControl(recaptcha_response_field=manual_challenge)>
<SubmitControl(submit=Create user)>
<HiddenControl(regfrom=full)>>

How can I fill in the following field?

<textarea cols="40" rows="3" name="recaptcha_challenge_field"></textarea>

<textarea cols="40" rows="3" name="recaptcha_challenge_field"></textarea>

is actually not a field that mechanize can fill out.