ordering of products limits to group of zipcode ..in delivery address

[charlestcr]

i am starting  new online shop ..http://www.orionsalescorporation.com/onlineshop/index.php......i can deliver products to small area of my district...how can i do this?...can i validate zip code of delivery adders of customer ...while entering delivery address...or can i give dropdownlist for zipcode ... so customer can select zipcode..from dropdownlist..

[traktap]

We have 2 Set of products. 

 

1) Available all over irrespective of the ZIP codes.  A List

2) Available only at specific ZIP code locations. B List

 

We want to display all products A List + Complete B List, when the guest has not logged in and his location or zipcode is not known.  

 

after the login when zip code is known . A List is shown + B List specific to his location is Shown

 

There are Modules which ask for Zip Codes and responds if the product is available at that location. But two drawbacks 

 

1) User has to enter the zip code to check. 

2) even if checked and shown not available , Still allows to purchase the item or product. 

 

Can anyone help to guide in the requirement.