call webService from win form

I have an webservice

I want to built small win form that connect to the web service.

VB Code:

<%@ WebService Language="C#" Class="WebService" %>
 
using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
 
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class WebService  : System.Web.Services.WebService {
 
    [WebMethod]
    public string checkMessage(int userID) 
    {
        System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
        doc.Load(Server.MapPath("XMLFile.xml"));
 
        System.Xml.XmlNodeList nodes = doc.SelectNodes("/NewDataSet//message[AssighmentTo='" + userID + "']");
        int i = 0;
        foreach (System.Xml.XmlNode node in nodes)
        {
            i++;
         }
 
         return i.ToString();
        
    }
    
}

how can I call this web service from win application?
thanks!