[SalesForce] How to set values for input list parameters for the webservice methods in XML Request for SOAP UI

I want to test my webservice using SOAP UI tool. I've loaded the WSDL in SOAP UI and it generated the request as given below. I know how to set input values for simple type. But i do not know how to set the values in SOAP UI for two List input parameters for the webservice method. Please note i exposed this class as unauthenticated in force.com site.

Action Url: http://gss-developer-edition.ap1.force.com/services/Soap/class/TestWebService

Given below is the webservice class,

global class TestWebService {
webService static String getFirstSOBrief(List<CustomerDTO> c, List<ProductDTO> p)  
{  
        System.debug('>>>>>>>>>>>>>>>>>>Customer List'+c);
        System.debug('&&&&&&&&&&&&&&&&&&Product List'+p);
        return c[0].CustomerNumber;  
} 

global class CustomerDTO {
    public String CustomerNumber {get;set;}
    public String Email {get;set;}
    public String FirstName {get;set;}
    public String LastName {get;set;}

    public CustomerDTO(String CustomerNumber,String FirstName, String LastName, String Email) {
        this.CustomerNumber = CustomerNumber;
        this.FirstName = FirstName;
        this.LastName = LastName;
        this.Email = Email;
    }
}

global class ProductDTO {
    public String MaterialNumber {get;set;}
    public String ProductName {get;set;}

    public ProductDTO(String MaterialNumber,String ProductName) {
        this.MaterialNumber = MaterialNumber;
        this.ProductName = ProductName;
    }
}

}

SOAP UI request below,

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tes="http://soap.sforce.com/schemas/class/TestWebService">
 <soapenv:Body>
  <tes:getFirstSOBrief>
     <!--Zero or more repetitions:-->
     <tes:c/>
     <!--Zero or more repetitions:-->
     <tes:p/>
  </tes:getFirstSOBrief>

Response:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns="http://soap.sforce.com/schemas/class/TestWebService" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

How to set values in the SOAP UI XML request for the List parameters List and LIst?

Update

Now i did as per the blog and got this error.

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tes="http://soap.sforce.com/schemas/class/TestWebService">
     <soapenv:Body>
      <tes:getFirstSOBrief>
         <!--Zero or more repetitions:-->

         <tes:c>
         <CustomerNumber>abcd</CustomerNumber>
         <Email>a@b.com</Email>
         <FirstName>fname</FirstName>
         <LastName>lname</LastName>
         </tes:c>

         <!--Zero or more repetitions:-->
         <tes:p/>
      </tes:getFirstSOBrief>
   </soapenv:Body>
</soapenv:Envelope>

Response:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">

soapenv:Client
There is no public member called 'CustomerNumber' in the Apex class 'CustomerDTO'