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？