how to update the request element value on the fly

Hi, I am a newbie of learning SoapUI. Suppose I have a sample request below, which sends a nickname:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 
   <soapenv:Header/>
   <soapenv:Body>
     <myRequest001>
     <nickName>dicky</nickName>
     </myRequest001>
   </soapenv:Body>
</soapenv:Envelope>

Here's the response received, which returns the real name:

<S:Envelope xmlns:S="http://schemas.xmlsoap.org/soap/envelope/">
   <S:Body>
      <myRequest001Response>
       <realName>sam wilson</realName>
      <result>SUCCESS</result>
     </myRequest001Response>
   </S:Body>
</S:Envelope>

Every time I send the request, I want the <nickName> element be populated with different value on the fly to be sent out. How can I do that? Should I use LoadUI to do that? Thanks!