we created one login entry screen. In that we want to retain the previously logged in user's id whenever the form is newly opened.
We used the concept of registry entries in such a way that the last entered user name will be stored in a registry entry(win_api_environment.write_registry) and whenever it is opened the last user name will be read (win_api_environment.read_registry).
But this is not working porperly giving an pl/sql error.. please help.
Registry will be client based. If your application is web based, then I don't think you can "write" anything on client's registry. There is a "webutil" utility available for accessing client side objects. But not sure if it can be used in this case.