Warning: require(/home/suncompu/public_html/sirifashion.in/administrator/components/com_virtuemart/helpers/config.php) [function.require]: failed to open stream: No such file or directory in /home/suncompu/public_html/sirifashion.in/plugins/system/vm2_cart/vm2_cart.php on line 24

is that file /home/suncompu/public_html/sirifashion.in/administrator/components/com_virtuemart/helpers/config.php there?

Would be extremely surprised if it wasn't as it contains all the definitions for Virtuemart..!

Please check