Nissan micra tailgate help?

Hi, i have a nissan micra 2003 plate which has the small little black button on the tailgate near the main button for the boot. When all car is locked i only have to press the small black button and it opens the boot. The main button for the boot is ok and doesnt open the boot if pressed when car is locked. Can anyone help me please as im worried someone will be bale to steal anything from my boot?

Thank you