Handling namespace and changing attribue values

[sreekanta]

Hi
I have a XML data of following format

<arod xmlns:a="Prod" action="D" type="Prod">
<ID>106</ID>
<VALUE>100</VALUE>
</arod>

I want to parse this XML data and form a new data as follows
<arod xmlns:a="Prod" action="U" type="Prod">
<Prod_sub>
<ID>106</ID>
</Prod_sub>
<VALUE>100</VALUE>
</arod>

I have 2 questions for the above data.

1. I'm not able to put the namespace xmlns:a="Prod" when forming <arod>. I'm able to put the action and type attributes in this tag. How to do this?

2. Now i want to change the value of the action to "U" if it's initial value is "D". if it is something otherthan "D" then i have to leave it as it is.

Plz let me know who should i do this

Thanks in advance
Sree