[xwiki-users] Edit and save custom document from view action

I have customized document (i.e. attached object of the custom class to document) and I'd like to change its status from the view mode. I tried to modify ClassSheet for view mode with following HTML: <form method="post" action="/xwiki/bin/edit/$doc.space/$doc.name"> <input type="hidden" name="Custom.Class_0_property" value="$myvalue"/> <input type="submit" value="Submit" name="action_save" class="button"> </form> but got error: Warning This request contains an invalid authentication information. Could anybody provide me some hints for me in the right direction? Thanks! Valdis