Why can't I re-run this program?

I have the following short G-code program I would like to run in EMC
multiple times without reloading it. In other words, I want it to run
every time I click on the run botton. This only does the X and Y axis
because at this time I am still working on the Z axis. This program
is to help me in making the bracket for the Z axis motor.

g20
f 2
g01 x1.5
g01 y .5
g01 x0
g01 y0
m30

The program runs fine, but only once. Should I be using M0 or M2 to
stop the program and leave it in a state that it will start over when
run is pressed? This program may seem a bit silly, but since my Z axis
is currently manual, I want to be able to move the Z by hand, and then
make another pass on this rectangular pocket.

Thanks

John Guenther