ODK Port Issue

Hello ,

I just configured ODK aggregate VM and changed the default port 80 to 81
in Tomcat server.xml settings .
In ODK Collect app, i configured the url with * * and provided the username and password in server

.When i press the *refresh *button , it shows me the form along with the
title "Demo" , which i have uploaded from the web site . But when i press
Get-Selected , it gives me this error after few seconds .

"failed to connect to / (port 80) after 30000ms . Connection
refused .

i see that internally it is trying to get the form from port 80 while i
have already configured the URL in in *Server
Settings *.
I am currently using port 80 for another application so cannot change it to
port 80 . i need to work on some other port .
Please suggest .

Many Thanks,
Muhammad Ali.