solving the listener problem and the browser problem

[rototem]

hello. I've just installed oracle database 10 personal and oracle developer 10 and made the configurations needed regarding the locat net service, but when open the forms builder and try to connect to the database, i get an error saying there is no listener, even if i did set it already.
Does anyone know how i could fix this problem?
I also have experience with oracle 8 personal edition, and while working in oracle 8 forms and running the form i user a runtime environment which was no a browser, but now i have a problem with version 10 because even if i've already setted the preferences-runtime the port(1521) the program still won't run the form , i only get a blank web page.I would much appreciate a t5* for this problem.