Question: is response.redirect always an http GET response? or it could be POST?....

Answer: 
Response.redirect uses only GET..It can't be a post..And in between what is the language?
Contrary to most answers here the redirected HTTP request is *only* GET if

* the original request was GET, or
* the status code was 303, or
* the status code was 301 or 302 and the original request was POST.