See:

• http://kb.mozillazine.org/Security.tls.version.*

You can set the security.tls.version.min and security.tls.version.max prefs to 0 to disable TLS and only leave SSL 3 enabled

• 0 means SSL 3.0, 1 means TLS 1.0, 2 means TLS 1.1, etc.

Hi

 open the firefox ,  type  about:config  in address bar.

click on " i'll be carefull , i promise " type " tls " in search field set following options to false :

  security.enable_tls;false
  security.enable_tls_session_tickets;false
  services.sync.prefs.sync.security.tls.version.max;false
  services.sync.prefs.sync.security.tls.version.min;false

and the end set value of " security.tls.version.min " and " security.tls.version.max " to 0

good luck ,

Note that the sync prefs specify whether to sync the specified pref is set to true.
So with services.sync.prefs.sync.security.tls.version.max to false the security.tls.version.max is not synced in case you use Firefox Sync.
The security.enable_tls pref is no longer used and can be reset and it will be removed on the next start.

• import "about:config" on the location bar
• search "tls"
• security.tls.version.min 1 = enable 0 = disable
• security.tls.version.max 1 = enable 0 = disable

• help persian - farsi

http://http://www.2telecomvpn2.info/firefox-version23-tls-disable