Pokemon Diamond save issues No$GBA both in game saves and supposed save states

I've recently downloaded both the No$GBA emulator and the Pokemon Diamond ROM because i was interested in the gameplay.
But to the point, after about an hour of gameplay, i decided i wanted to save, quit, and go do something for a minute.
I returned, activated the program and was somewhat disappointed to see the opening menu for a new character. Being as cautious as i am, i dropped what i thought was a savestate and an in game save. Hovever, it turned out i saved a snapshot (naturally i expect the ability to create and load a save state was in the first menu, Generic ROM gamer :D) and would not let me load it, claiming i was trying to load a cartridge and not a save. Since i'm pretty new to messing around with DS function of No$GBA (well the whole emulator really, i've been sticking to VBA lately), can someone learn me in the ways of saving both through savestates and ingame saves? Or perhaps if it was a savestate, teach me how to load it? Would really appreaciate it.
I've also toyed around with the save type and some other things in the menu to get the rom playing, so i might need some explainations for that as well

Thanks.