In the last decade several scenarios for the formation of globular clusters have been suggested. One of these models starts with an OB-association exploding near the center of a molecular cloud (Brown et al., ApJ 376, 115 (1991)): The expanding shell sweeps up the cloud material and later the expansion will be decelerated or stopped by the external pressure of the ambient hot gas. The shell itself can break into fragments and form stars. If the total energy of these stars is negative, they will recollapse and eventually form a bound system. According to this idea the dynamics of a thin stellar shell has been studied.