I want to understand how this page: http://www.indiapost.gov.in/pin/pinsearch.aspx is getting data from server. When this page loads: 1) click on District 2) Select a district from the combo box and press Search button Open the page source of the resulting window. I want to know what's there in the values of the form variables: __VIEWSTATE & __EVENTVALIDATION It does not seem to be encrypted using encode_base64 php function. Anurag