ssh script question

[dreamwvr]

hi,
   anyone successful i writing a script that automates ssh logins 
via RSA? i have been able to establish the connection but ssh
tells me that STDIN is not a tty therefore one is not assigned and 
it fails to see my 'manual' input of passphrase at that point .. any 
ideas how to workaround and get ssh to allow for passphrase driven
access via a script that prompts for this using ssh?                
                                                          TIA