Please do not tell me to do a search, or read the FAQ's as i have done both.

I KNOW this has been asked before, but i cannot find the answer anywhere!
How do i use the mame software to "flip" a vertical game to play on a horizontal monitor?
My Galaga plays great, only it is left to right, i want it up and down!
I am using the newest version of mame and Mamewah. I am new to MAME and just need this little help as i do not want to build a vert cab. I have tried using the "tab menu" and play with the "dip switched" and still cannot figure out how to flip the "flipping thing"
Thanks and PLEASE let me know how to do this, i NEED MY GALAGA FIX!!
Thanks in advance to all,
Ken