run ssh in emacs

[Haines Brown]

I want to gain access to two machines on the LAN by means of ssh. In
order to use emacs as a file manager, I do # ssh -Y remotehost, and then
start emacs on that host, and split its window. One buffer accesses
files on the remote machine, and I want the other buffer to access the 
local machine in order to use emacs to transfer files between the
hosts. However, this does not work.

For example, if I bring up a shell in emacs (C-!) and do ! ssh localhost,
I get:

  Pseudo-terminal will not be allocated because stdin is not a terminal.
  ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
  Permission denied, please try again.
  ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
  Permission denied, please try again.
  ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
  Permission denied (publickey,password).

Is the problem not having access to pseudo-terminal, or it that there is
no /usr/bin/ssh-askpass file? How do I construct that file. Why can't I
just provide the password when prompted for it?

Haines Brown