xmlns namespace

[Sudhakar Kurumella <kurumella@yahoo.com>]

Hi All,
   I have basic doubt regarding writing xml docs. The
"namespace" is bothering me when i am looking at
example in any XML book. Pls look at the following
code :   
  <?xml version="1.0" encoding="UTF-8"?>
<PurchaseOrder xmlns="urn:oreilly-jaws-samples">
	<shipTo country="US">
		<name>Joe Smith</name>
		<street>14 Oak Park</street>
		<city>Bedford</city>
		<state>MA</state>
		<zip>01730</zip>
	</shipTo>
	<items>
		<item partNum="872-AA">		
<productName>CandyCanes</productName>
	<quantity>444</quantity>
	<price>1.68</price>
	<comment>I want candy!</comment>
		</item>
	</items>
</PurchaseOrder>

In the above code "<PurchaseOrder
xmlns="urn:oreilly-jaws-samples">", what is this
urn:oreilly-jaws-samples.If i am writing my own code
what all the stpes i need to take to give this xmlns
on my own..i'll appricate if anybody throw some light
on it..

thanks in advance...
Sudhkar K

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