Hi all,
      This is the code which is generated from the wsdl2apex, how to write webservice for
this code, please help me out.


public class dbappsMywebservice1WsdlTypes {
    public class placeOrderElement_element {
        public Integer pProductId;
        public Integer pCustomerId;
        public Integer pQuantity;
        private String[] pProductId_type_info = new String[]{'pProductId','http://www.w3.org/2001/XMLSchema','int','1','1','true'};
        private String[] pCustomerId_type_info = new String[]{'pCustomerId','http://www.w3.org/2001/XMLSchema','int','1','1','true'};
        private String[] pQuantity_type_info = new String[]{'pQuantity','http://www.w3.org/2001/XMLSchema','int','1','1','true'};
        private String[] apex_schema_type_info = new String[]{'http://dbapps/MyWebService1.wsdl/types/','true'};
        private String[] field_order_type_info = new String[]{'pProductId','pCustomerId','pQuantity'};
 public String endpoint_x = 'http://www.example.com/webservice.asmx';
    }
    public class placeOrderResponseElement_element {
        public String result;
        private String[] result_type_info = new String[]{'result','http://www.w3.org/2001/XMLSchema','string','1','1','true'};
        private String[] apex_schema_type_info = new String[]{'http://dbapps/MyWebService1.wsdl/types/','true'};
        private String[] field_order_type_info = new String[]{'result'};
 
    }
}


public class dbappsMywebservice1Wsdl {
    public class MyWebService1SoapHttpPort {
        public String endpoint_x = 'http://192.168.200.78:8888/PLSQLWEB-AppsWS-context-root/MyWebService1SoapHttpPort';
        private String[] ns_map_type_info = new String[]{'http://dbapps/MyWebService1.wsdl/types/', 'dbappsMywebservice1WsdlTypes', 'http://dbapps/MyWebService1.wsdl', 'dbappsMywebservice1Wsdl'};
        public String placeOrder(Integer pProductId,Integer pCustomerId,Integer pQuantity) {
            dbappsMywebservice1WsdlTypes.placeOrderElement_element request_x = new dbappsMywebservice1WsdlTypes.placeOrderElement_element();
            dbappsMywebservice1WsdlTypes.placeOrderResponseElement_element response_x;
            request_x.pProductId = pProductId;
            request_x.pCustomerId = pCustomerId;
            request_x.pQuantity = pQuantity;
            Map<String, dbappsMywebservice1WsdlTypes.placeOrderResponseElement_element> response_map_x = new Map<String, dbappsMywebservice1WsdlTypes.placeOrderResponseElement_element>();
            response_map_x.put('response_x', response_x);
            WebServiceCallout.invoke(
              this,
              request_x,
              response_map_x,
              new String[]{endpoint_x,
              'http://dbapps/MyWebService1.wsdl/placeOrder',
              'http://dbapps/MyWebService1.wsdl/types/',
              'placeOrderElement',
              'http://dbapps/MyWebService1.wsdl/types/',
              'placeOrderResponseElement',
              'dbappsMywebservice1WsdlTypes.placeOrderResponseElement_element'}
            );
            response_x = response_map_x.get('response_x');
            return response_x.result;
        }
    }
}