Why my url does not match my page?

Hi!

When I run my web pages, the first page is Default.aspx. When I click a
button "GO", it navigates to an action page and it is Action.aspx. However,
the url appears in the browser is htt://:www.localhost/default.aspx instead
of http://www.localhost/Action.aspx

Why this is the case. I found there is always a page delay. For example, if
I clicked "Next" in my Action page, it will direct me to the Display page but
the url is Action.aspx instead Display.aspx.

Please help me with this.
Thanks,
Aijun.

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Aijun