已知：
1,Server URL： https://dev.truemoney.co.th/cpg/CPGWSOnline/services/OnlineTopupService
2,XML Schema：
<?xml version = '1.0' encoding = 'UTF-8'?> 
  <schema targetNamespace="http://webservice.gateway.payment.eit.ti.com" 
xmlns="http://www.w3.org/2001/XMLSchema" 
xmlns:impl="http://webservice.gateway.payment.eit.ti.com" 
xmlns:intf="http://webservice.gateway.payment.eit.ti.com" 
xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> 
   <element name="performServiceResponse"> 
    <complexType> 
     <sequence> 
      <element name="performServiceReturn" nillable="true" type="xsd:string"/> 
     </sequence> 
    </complexType> 
   </element> 
   <element name="performService"> 
    <complexType> 
     <sequence> 
      <element name="xmlInput" nillable="true" type="xsd:string"/> 
     </sequence> 
    </complexType> 
   </element> 
  </schema> 
3,Request：
<?xml version=”1.0” encoding=”UTF-8” ?>  
<TOPUP_REQUEST> 
       <mesg_type>verify</mesg_type> 
      <cpgmerchantId>800000700</cpgmerchantId> 
       <cpgpassword>verify</cpgpassword> 
       <trans_id>2093843982094</trans_id> 
       <send_date>20060621</send_date> 
       <send_time>120501</send_time> 
       <bank_code>002</bank_code> 
      <bank_account>17129081234</bank_code> 
       <branch_code>180</branch_code> 
       <channel>A</channel> 
       <term_id>S424B180A251</term_id> 
       <service_code>TMNTOPUP</service_code>       
       <cust_no>0843454433</cust_no> 
       <amount>50000</amount> 
       <ref1>45664321****</ref1> 
       <ref2>LOTUS</ref2> 
</TOPUP_REQUEST> 
在C# winform中如何调用这个webservice完成工作？