>I am using
>

>Response.Redirect ("pagina.aspx")
>

>to send the user for a page.
>But, as to make this using frames and to send for a page in frame name="centro"?

I’m not sure I understand what it is that you are saying but I’ll take a shot by saying that:
I usually do my frame pages as strait .HTM pages with the frames calling out to .ASPX pages.

You should have no problem setting things like :

		<frameset cols="164,100%">
			<frame name="contents" src="LeftMainMenu.aspx">
			<frame name="main" src="Main01.aspx">
		</frameset>

And making calls from any frame like:

<A target='main' href="//www.microsoft.com">

Choosing which frame a request goes to happens on the client side.