PHP curl screen scraping - Problem with .aspx pages

[mknath7]

I have been screenscraping several websites for my company.

I'm facing a problem now with .aspx pages:

 

[*]The form that needs to be submitted is in index.aspx

[*]The POST variables need to be sent to the same page using CURL, that is index.php

[*]I got an error, invalid viewstate

[*]Now, i tried to scrape VIEWSTATE variable & posted it back to index.php

[*]Again i got the same error, invalid VIEWSTATE

 

Please help me in submitting VIEWSTATE variable successfully. What should be done??