plotting area in multiplots

[Lu Guoqiang]

How to keep the widths of two (or more) plots the same when their respective
ylabels differ significantly? Say the ylabels for subplot(211) are 0, 10,
15, 20 and the for subplot(212) are 0, 10000,15000, 20000, then the
resulting two plots will have the same width INCLUDING the labels. As a
result, the actual plot area for subplot(212) will have a narrower area
because the ylabels take more space.

Is there a way to work around?

G. LU