According to my knowledge,with out giving port no. we can't access resources(our application) in server. There is no risk at all mentioning port no. of the server. [ October 16, 2008: Message edited by: Reddy Naidu Chowdhary ]
Based on the url given I see that you are using http protocol and default port for this protocol is 80. So if you can run your webserver on this port, you can access the required page without giving the port.