This (version 1) runs the motor until the Touch Sensor is pressed.  Then stops the motor.

 This (version 2) runs the motor forward, waits for touch, then backward, waits for touch.  If you want to do this several times in a row, you could copy-and-paste this second of code over and over.  (But there is a better way, using loops; see version 3.)

This (version 3) does the forward/wait/backward/wait sequence in a While Loop, and runs forever.

This (version 4) accomplishes the same as version 3, but with only ONE motor command.  Each time the loop executes (each time the button is pressed), the loop counter is used to determine the direction. If it is even, the motor goes forward; if it is odd, the motor goes backward.