how to show the params value in page.alert

hi to everyone how to show the params value in page.alert

page.alert('Your image has been uploaded sucessfully'
+'params[:image][:uploaded_data].original_filename')

what about:

page.alert('Your image has been uploaded sucessfully' +params[:image]
[:uploaded_data].original_filename)

without the parentheses around the variable

or a bit more Rails like:

page.alert("Your image has been uploaded sucessfully #{params[:image]
[:uploaded_data].original_filename}")