C172 STUDENT PLT DEPARTS THE RWY ON A XWIND LNDG. NO DAMAGE OR INJURY.

Narrative

I WAS A STUDENT PLT FLYING A C172 DOING PATTERN WORK; AND COMING IN ON MY 4TH LNDG ON RWY 23L. THE TWR HAD CLRED ME FOR THE OPTION. THE 'RED OVER WHITE' INDICATION FROM THE VASI WAS CONSISTENT THROUGH THE ENTIRE LNDG. I WAS PERFECTLY LINED UP WITH THE CTRLINE. I WAS VERY LOW RIGHT OVER THE GND RIDING THE GND EFFECT WHEN THE R WING WENT UP WHICH CAUSED THE L MAIN WHEEL TO TOUCH DOWN. I INSTINCTIVELY PULLED QUICKLY ON THE THROTTLE BUT IT WAS ALREADY AT IDLE. I PULLED BACK ON THE YOKE TO FLARE AND THE AIRPLANE SKIPPED ONCE ON THE GND. THERE IT WAS -- ALL WHEELS ON THE GND -- AND I FOUND MYSELF HEADING QUICKLY TOWARD THE GRASS. I THEN CAME TO A STOP IN THE GRASS AND ASKED WHAT TO DO FROM THE CTL TWR. THE TWR ASKED ME IF I WANTED TO JUST TAXI OFF THE GRASS AND THEN THEY SUGGESTED THAT I SHUT DOWN. THE FIRE STATION WAS CALLED; SHOWED UP; AND IT BECAME A NON-EVENT. I THINK IT WAS THE BEST CHOICE TO SHUT DOWN AND AVOID A PROP STRIKE ON THE EDGE OF THE PAVEMENT. ALSO; THIS IS AN EXAMPLE THAT EVEN LNDG ON A 150 FT WIDE RWY CAN BE PROBLEMATIC IN A XWIND.