I'm still new here so I'm sorry if I ever missed a thread with a similar topic. Yes, I looked around the rest of the Forums, but I didn't find anything useful, so I will just post here.
I'm playing a game in the GBA (YGO: Eternal Duelist Soul), but I can't seem to fix the controls. When I double click the screen, it automatically chooses a key for me-something I didn't assign. Like, I double click: It assigns 'F' for the Up control and then I can't change it, whatever button I choose...It just won't register. When I go move next to Down, Left, Right, Button A, Button B,etc. it also automatically chooses the key that's registered in the 'Up' control (in this case, 'F' -- for ALL commands). There's also something else minor: the cursor that allows you to "type" in your desired commands doesn't move away from the utmost, default "left" position.

Please, is there a way to fix this? Maybe I'm just too newbie in knowing  how to ACTUALLY change the commands... Anyone?

cl0ne : Use the alternate emulator "Mednafen"

To use, just load the game like you normally would. Then when the game window pops up, click the link found in the upper left hand corner labeled, "Play using Mednafen"

The only drawback here is that you will have to start from the beginning in any games that you may have saved using the default GBA emulator since the save states are not compatible between emulators.

One good thing though is that this emulator supports full-screen by holding alt+enter on your keyboard with the game window active.

Please let me know if you have any further questions regarding this matter.

Happy gaming!