well ... first tip, LoginForm is not supposed to be or contain your main method, it's a tool that's to be used, nothing more.

just put the main method in a new class and use that to call the LoginForm and the DictionaryForm.

when you've done that, re-read the posts above and put those thoughts into a bit of code.
for what I can see in the code you attached, you haven't tried to code it yet, so it's nothing but natural that it doesn't work yet