Watir-webdriver, cannot interact with a div popup

Question

I cannot figure out a way to interact with the highlighted HTML:

When I click on a link, an interactive modal appears, which has a table to allow user to buy parts. Also, the modal has links that open up new sections within the modal.

I have tried to write step definitions but cannot get test to pass. See below for my (latest attempt) code:

When /^I click on the Buy icon of loan part selected$/ do
  @browser.div(:id, 'modal_loan_parts_table').link(:text, 'Buy').click
end

The error I keep getting is element not located . Can someone please direct me to enlightenment?

Here is the error that occured:

  unable to locate element, using {:id=>"modal_loan_parts_table", :tag_name=>"div"} (Watir::Exception::UnknownObjectException)
  ./step_definitions/secondarymkt_buying_lp.rb:62:in `/^I click on the Buy icon of loan part selected$/'
  secondarymkt_buying_lp.feature:27:in `When I cllick on the Buy icon of loan part selected'

Many Thanks Guys!

Answer 1

I found the solution without using xpath. Here is my code and it works:

When /^I click on the Buy icon of loan part selected$/ do
  @browser.div(:id, 'details-ajax-modal').wait_until_present
  @browser.div(:id, 'details-ajax-modal').exists?
  @browser.link(:class, 'modal-buy').wait_until_present
  @browser.link(:class, 'modal-buy').click
end

Many thanks to everyone.