How to get value through xpath for repeating tags,it's like key value pair

I am developing very dynamic application. I have the below xml as input request.I am querying below through xpath.For example ,I have to get the perticular value of UpdateTime.how can i write the xpath to get the value of this field.The problem is the order of AdditionalData tag can be change.

What can i put the logic here...?

<InputData>
  <AdditionalData>
    <Name>TransmissionDatetime</Name>
    <Value>20101130121706</Value>
  </AdditionalData>
  <AdditionalData>
    <Name>UpdateDate</Name>
    <Value>20101130121604</Value>
  </AdditionalData>
  <AdditionalData>
    <Name>TimeofArrival</Name>
    <Value>20101130161705</Value>
  </AdditionalData>
  <AdditionalData>
    <Name>P开发者_如何学运维art</Name>
    <Value>20101130161236</Value>
  </AdditionalData>
  <AdditionalData>
    <Name>SiteID</Name>
    <Value>1520537</Value>
  </AdditionalData>
</InputData>

Can any one help me and give some idea.....???

You haven't made the requirement very clear, but I suspect you are looking for

/InputData/AdditionalData[Name='UpdateDate']/Value

try this: /InputData/AdditionalData[Name='UpdateDate'] ?

have a look at: http://www.w3schools.com/XPath/xpath_syntax.asp

For a xpath test and development tool try XPathVisualizer...

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