  In this paper, we discuss gravitational collapse of spherically symmetric
spacetimes. We derive a general formalism by taking two arbitrary spherically
symmetric spacetimes with $g_{00}=1$. Israel's junction conditions are used to
develop this formalism. The formulae for extrinsic curvature tensor are
obtained. The general form of the surface energy-momentum tensor depending on
extrinsic curvature tensor components is derived. This leads us to the surface
energy density and the tangential pressure. The formalism is applied to two
known spherically symmetric spacetimes. The results obtained show the regions
for the collapse and expansion of the shell.
