Login Help

Hey there, I'm very new to Java and I'm busy making a login frame for a little school project we're doing.
Everything's working perfectly except I can't get my two panels to fit next to each other seamlessly.

I want it to look like this:

I'd prefer a simple solution if possible, I'm also using NetBeans so if there's a way to fix this there it would greatly be appreciated

It's a bit difficult to guess at the problem without some code - can you show us what your code looks like?