I have source code of popular Shopping Cart script in which 

i wish to add a few features.

You qualify for the job IF: You have customized/modified 

features of some popular open source project - or have 

developed a plugin/module/extension of it (note that you 

DON'T qualify if you have just USED the open source)

The shopping cart source code I have is of 'Interspire Shopping Cart '. 

http://idn.interspire.com/categories/Shopping-Cart/
http://idn.interspire.com/articles/33/1/Interspire-Shopping-Cart-Modules-Documen tation/Page1.html

Please share your portfolio where you have customized/modified/ developed a plugin/module/extension for popular opensource cart/CMS.

I will share the 'specifications' to relevant candidates.

nature of hiring is urgent so apply ASAP.