Make object stop moving at certain point

I have a randommove function that moves an object along randomly. I have to put this inside of a Do Together loop (along with another object moving randomly - a race). However, they never stop moving!

It says to put the Do Together inside of a While loop, but I have no idea how to get them to stop.

[Scott300]

while variable is true
{
Code
}
and set the variable to false when you want the while to stop, but the while will keep looping till the variable is not equal to true.