Hi, I would like to simulate a postback on an asp.net page. I explain myself, let's say i have a page with an asp "form" so the postback is performed on the submit button click with: _WebForm_DoPostBackWithOptions(...) -> __doPostBack(...) I would like to perform the same request but with an xmlhttprequest object. i found that, in fact, i need to send by post method the values of __VIEWSTATE, __EVENTTARGET and __EVENTARGUMENT. Actually i know that my eventtarget is the submit link name and the event argument is empty (in my case). The view state is an hidden field in the page. I understood that __VIEWSTATE contains the (serialized ) values of the active controls in the page, so by sending the viewstate the page will be able to find the values and perform the correct operations. So how is generated this field before the "send" operation If anybody knows it could really help me. If im wrong in one of the statements i wrote, please tell me Thank you by advance Clement