c# - WCF - SOAP Action mismatch error while testing with SoapUI -

how fix this?

>  <s:envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" > xmlns:a="http://www.w3.org/2005/08/addressing">    <s:header> >       <a:action s:mustunderstand="1">http://www.w3.org/2005/08/addressing/fault</a:action> > </s:header>    <s:body> >       <s:fault> >          <s:code> >             <s:value>s:sender</s:value> >             <s:subcode> >                <s:value>a:actionmismatch</s:value> >             </s:subcode> >          </s:code> >          <s:reason> >             <s:text xml:lang="en-us">the soap action specified on message, '', not match http soap action, > 'xx.xxx.webservices.xxxxservice/xxxxservice/authenticateuser'.</s:text> >          </s:reason> >          <s:detail> >             <a:problemheaderqname>a:action</a:problemheaderqname> >          </s:detail> >       </s:fault>    </s:body> </s:envelope> 

configure soapui send http header:

soapaction=xx.xxx.webservices.xxxxservice/xxxxservice/authenticateuser