asp.net mvc 3 - MVC3 return a File always in a new tab without replace the old one -

i have form target="_blank" posts, process , return pdf file in new tab, problem is:

when first time, it's ok, when again, instead of opening new tab, replaces old 1 new content!

and if i'm using internet explorer, posts parameters null, in case need close new tab, , again

controller:

public actionresult submitreport(string parameter) {    // code    return file(stream, "application/pdf"); }

view:

@using (html.beginform("submitreport", "resumopagamentos", formmethod.post, new { area = "ci3s", @target = "_blank" })) {   // etc.. etc... }

html target values case-sensitive.

_blank (capital b) not special _blank value (which opens new tab), tab named _blank, reused if exists.

Brande