XSL output solution

Hi,
      I am new to XSL and I'm having issues coming up with a solution for this problem.
      I have the XML structure below:
      <Root>
      <CUs>
            <CU>                  
                  <ContractNr>12345</ContractNr>                  
                  <FullName>Alison full</FullName>            
                  <id>111</id>      
            </CU>
            <CU>                  
                  <ContractNr>45678</ContractNr>                  
                  <FullName>Nancy Full</FullName>      
                  <id>222</id>                  
            </CU>            
      </CUs>      
      <Results>
            <Result>
         <AccountId>0000-0000-0005</AccountId>
         <OrgNr>12345</OrgNr>
             <Status>Active</Status>
             <FullName>Alison full</FullName>
        </Result>
        <Result>
          <AccountId>0000-0000-0005</AccountId>
          <OrgNr>45678</OrgNr>
          <Status>Active</Status>
          <FullName>Steve Full</FullName>
        </Result>                  
      </Results>      
</Root>
      
      
      I need using XSLT to output the following XML result:
      <Output>
       <Customer>
        <ContractNr>45678</ContractNr>      
        <FullName>Nancy Full</FullName>
        <Status>Active</Status>
       </Customer>
      </Output>
      
      What i need is to loop into all <CU> and using the <ContractNr> value to finds its match <Result>.  The <OrgNr> of a Result will contain the same value as <ContractNr> in a CU.
      Once the 2 records are matched I need to compare the FullName from the <CU> against the FullName of the <Result>. If the FullNames are not the same then output the XML above.
      If the fullname is the same then do nothing.
      So the output xml above is what I'd get if i use the input xml at the begining.      
      Thanks!