XML : Java script to parse xml

I want to read xml file using java script, the xml contains below code.

Warranty CGL609

  </my:Project_Details>  <my:Change_Details>      <my:StartDateTime>2014-09-02T16:00:00</my:StartDateTime>      <my:EndDateTime>2014-09-03T18:00:00</my:EndDateTime>      <my:Change_Number>IM3091094</my:Change_Number>      <my:TaskNumber></my:TaskNumber>      <my:DryRunDate xsi:nil="true"></my:DryRunDate>      <my:FirstLiveRunDate>2014-09-02</my:FirstLiveRunDate>      <my:WarrantyEndDate>2014-09-03</my:WarrantyEndDate>      <my:field8></my:field8>  </my:Change_Details>  <my:Release_Details>      <my:HostGroup>          <my:HostsTable>              <my:Domain_and_Host>hostname</my:Domain_and_Host>              <my:Project></my:Project>          </my:HostsTable>      </my:HostGroup>      <my:DeployStartDateTime>2014-09-02T16:30:00</my:DeployStartDateTime>  </my:Release_Details>  <my:Header>      <my:RequestID>sd2914</my:RequestID>      <my:RequestNumber>2914</my:RequestNumber>      <my:RequestHeader>sd</my:RequestHeader>  </my:Header>  <my:Release_Section>    

I want to retrieve values of" my:Project_Title , my:Project_Code, my:Change_Number and my:Domain_and_Host". I am very new to scripting, please help.

Thanks