Source:Open Clip Art Using Under Public Domain Attribution
The shipment plugins can configured by zip code to make the shipment method only available within a range of zip code. But not every country has zip code. So, I need to customize the shipment plugin.
To do this customization, I need to put my own code in:

PHP

I found the price in all products at my virtuemart are disappeared. I checked all products have price and the template has the price field too.
I figured the problem in Currency. Please check Virtuemart-> Configuration-> Currency and make sure Positive Format filled(like the image above).

I like to use chrono forms for building forms in Joomla. That is very powerful, you can have form to email functions and all forms elements, such as text box, option box and drop down box. Moreover, the administration interface is very easy to use. You can drag and drop elements to a form, then you can construct a form you want.

Lastly, it has a free version. So far, only one limitation I found is all forms need to have a link back to chrono forms. Well, that is fair.

I am using Virtuemart 2.6.0. I have no problems to install it. When I tried to add product categories and product, I got this error :vmError: VmTableData Sef Alias in record is missing! Can't save the record with no Sef Alias..
Finally, I fixed it by upgarding php from 5.2 to 5.4, then it fixed.

I am just about to build a new website for a client with Joomla 3.2. However, after I checked the requirement of Joomla 3.2, that requires PHP 5.4+. That doesn't support by the client's webhost yet.

If you plan to have Joomla 3.2, please check with the web hosting company first. I have worked with a number of budget web hosting companies,they are using php 5.3.x. Thus, before you install Joomla 3.2, please please check the php version of web hosting company!