String interpolation

 addressFile = File.open("Alarm.txt")

  #temp = "100 Avery St" ## This works
  #destination = temp.gsub!(' ','+')
  address = addressFile.read()
  destination = address.gsub!(' ','+') ##This doesnt work
  addressFile.close()
  uri =URI("http://open.mapquestapi.com/directions/v1/route?key=&ambiguities=ignore&from=1600+Spring+St,Parkersburg,WV&to=#{destination},Parkersburg,WV&callback=renderNarrative&outFormat=xml")
  directions = Net::HTTP.get(uri)
  file = File.open("directions.xml", 'w')
  File.write(file, directions)
  parseDirections()