can't open an xcl workbook on a mac with rb-appscript

[Arti Singh]

I get an errror when I try to open a workbook

require "appscript"
include Appscript

excel=app('Microsoft Excel')
excel.activate
workbook=excel.open_workbookworkbook_filename=>"Macintosh
HD::Files:ata.xlsx")

Does any one here have any ideas as to what I can do? I am out of ideas

/opt/local/lib/ruby1.9/site_ruby/1.9.1/appscript.rb:467:in `block in
_send_command': Unknown keyword parameter: :workbook_filename
(ArgumentError)
from /opt/local/lib/ruby1.9/site_ruby/1.9.1/appscript.rb:464:in `each'
from /opt/local/lib/ruby1.9/site_ruby/1.9.1/appscript.rb:464:in
`_send_command'
from /opt/local/lib/ruby1.9/site_ruby/1.9.1/appscript.rb:643:in
`method_missing'
from test.rb:6:in `<main>'