  We study the effective potential of a scalar field based on the 5D gauged
supergravity for the RS1 brane model in terms of the brane running method. The
scalar couples to the brane such that the BPS conditions are satisfied for the
bulk configuration. The resulting effective potential implies that the
interbrane distance is undetermined in this case, and we need a small BPS
breaking term on the brane to stabilize the interbrane distance at a finite
length. We also discuss the relationship to the Goldberger-Wise model.
