Different Wheel Programs

Does anyone know how to program wheels to the joysticks differently than the program below it will be appreciated if you do.

motor[motorname] = (vexRT[Ch2] + vexRT[Ch1])/2; //(y+x)/2
motor[motorname] = (vexRT[Ch2] + vexRT[Ch1])/2; //(y+x)/2
motor[motorname] = (vexRT[Ch3] - vexRT[Ch4])/2; // (y-x)/2
motor[motorname] = (vexRT[Ch3] - vexRT[Ch4])/2; // (y-x)/2

motor[motorname] = vexRT(Ch2);
motor[motorname] = vexRT(Ch3);

Thanks!!! It works great now!!!