  An effective Chern-Simons theory for the Abelian quantum Hall states with
edges is proposed to study the edge and bulk properties in a unified fashion.
We impose a condition that the currents do not flow outside the sample. With
this boundary condition, the action remains gauge invariant and the edge modes
are naturally derived. We find that the integer coupling matrix $K$ should
satisfy the condition $\sum_I(K^{-1})_{IJ} = \nu/m$ ($\nu$: filling of Landau
levels, $m$: the number of gauge fields ) for the quantum Hall liquids. Then
the Hall conductance is always quantized irrespective of the detailed dynamics
or the randomness at the edge.
