Melon DS core and DeSmuME DS (codes not working) Help!

I’m using Melon DS core to play Mario and Luigi Partners in time and the codes like max money/coins don’t work.

I tried DeSmuME DS core and the codes “do” work but I can’t switch back and forth between screens with a tap of the button like Melon DS. I have to go into the DeSmuME options and select what screen I want to currently view and that takes like 20 seconds…So I guess another question I have is:

Is there a way to easily switch back and forth between the two screen layouts top and bottom with DeSmuME without having to completely go into the options each time? Is there no option to toggle back and forth between screens with DeSmuME like there is with Melon DS?

If there is I’d just use DeSmuME because the codes are working with this core…Any help would be much appreciated.

One of my questions was answered. You can indeed switch screens instantly with DeSmuME by pressing in the right analog stick.

So my second question is: Why don’t codes work in Melon DS core? Did that emulator not have a cheat function?