The best thing you can do, if you need a script to login to a host, is configure a ssh key between the hosts.
I pretty much lifted this from the page
First, install OpenSSH on two UNIX machines, hurly and burly. This works best using DSA keys and SSH2 by default as far as I can tell. All the other HOWTOs I've seen seem to deal with RSA keys and SSH1, and the instructions not surprisingly fail to work with SSH2.
On each machine type ssh somemachine.example.com and make a connection with your regular password. This will create a .ssh dir in your home directory with the proper perms.
On your primary machine where you want your secret keys to live (let's say hurly), type
ssh-keygen -t dsa
This will prompt you for a secret passphrase. If this is your primary identity key, make sure to use a good passphrase. If this works right you will get two files called id_dsa and id_dsa.pub in your .ssh dir. Note: it is possible to just press the enter key when prompted for a passphrase, which will make a key with no passphrase. This is a Bad Idea ™ for an identity key, so don't do it! See below for uses of keys without passphrases.
scp ~/.ssh/id_dsa.pub burly:.ssh/authorized_keys2
Copy the id_dsa.pub file to the other host's .ssh dir with the name authorized_keys2. Now burly is ready to accept your ssh key. How to tell it which keys to use? The ssh-add command will do it. For a test, type
ssh-agent sh -c 'ssh-add < /dev/null && bash'
This will start the ssh-agent, add your default identity(prompting you for your passphrase), and spawn a bash shell. From this new shell you should be able to:
You should be able to log in