Open popup from JSP - Servlet ??

Could some Java guru please help ?? I have
a JSP, from inside which of which I do a POST to a Servlet, which then
does some operations inside its 'doPost' method and at the end
dynamically generates a Web page. Currently,
this page is rendered inside a frame. How do I
make the page be rendered inside a popup window ? Any hints,
suggestions would be of
immense value - thanks in advance for your
help.
.

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