$ ./674272.pl
POST .../Browse.aspx?MyToken=632797078501515540 [aspnetForm]
  __EVENTTARGET=                 (hidden readonly)
  __EVENTARGUMENT=               (hidden readonly)
  __VIEWSTATE=/wEPDwUJ           (hidden readonly)
POST .../Browse.aspx?MyToken=632797078501515540 [aspnetForm]
  __EVENTTARGET=mynewvalue       (hidden readonly)
  __EVENTARGUMENT=               (hidden readonly)
  __VIEWSTATE=/wEPDwUJ           (hidden readonly)