Web service call time given SSL error in ASP .net

<!-- User Validation API at LOGIN module Begin-->
   <system.serviceModel>
  <bindings>
      <basicHttpBinding>
        <binding name="UserValidateSoap">
          <security mode="Transport">
            <transport clientCredentialType="None" />
          </security>
        </binding>
        </basicHttpBinding>
    </bindings>
   <client>
     <endpoint address="https://localhost/abcd.asmx" binding="basicHttpBinding" bindingConfiguration="UserValidateSoap" contract="UserValidate.UserValidateSoap" name="UserValidateSoap" />
   </client>
 </system.serviceModel>
<!--  User Validation API at LOGIN module End-->