Problems with ajax in Rails 3

Dear all:
     I'm new to Rails and I've encountered some problems with ajax in
Rails 3. My project is on a Ubuntu 10.04 LTS machine with ruby v1.8.7
and rails v3.0.0.

I've changed my rails.js file according to :

http://github.com/rails/jquery-ujs/blob/master/src/rails.js

and also changed my javascript_include_tag to these three paths:

  1."http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"
  2."http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.2/jquery-ui.min.js"
  3."rails.js"

Everything works just fine except a controller with a ssh connection
behavior.

In my malfunctioned controller:

def remoteStatus
    @ip = params[:server][:ip]
    @sshid = params[:server][:sshid]
    @sshpass = params[:server][:sshpass]
    Net::SSH.start(@ip, @sshid, :password => @sshpass) do |
  session.exec!("free | awk 'NR==2 {print rate = $3/$2*100}'") do

channel, stream, data|

            @memusage = data
  end
    end
    respond_to do |format|
        format.js
    end
end

In the remoteStatus.js.erb I have:

$('#status_div').append("<%=@memusage%>")

I am pretty sure that I can have the ssh connection result in variable
@memusage. But it seems that it never appends to the status_div block in
the corresponding view. I'm wondering if I am missing something
detailed. Can anyone help me here,please and thanks!

Best regards