how change résolution for shoot m up

[spyloops]

Hi , im quite new in the hyperspin World ,

and i need you experience,
well ,i have a lot of MAME roms , everything work perfectly just an issue with vertical games like shoot s m up ,1947 etc ....
the game are totally stretch and don t look good, i looking a way to have same thing like my Cave roms, a perfect verticale centered image .

i got a cave emu who use the same module than MAME , MAME.ahk and RetroArch.AHK, but my Cave games are not stretch at all . so what can i do to fix my Mames verticals games ,
thx for your help

[spyloops]

ok i find it by my self ,
if someone have  the same issue, it s in mamepgui.exe > files  proprieties> General > osd screen