using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication4
{
    public partial class Form1 : Form
    {
        MSOSOAPLib30.SoapClient30Class SoapClient30Class;

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SoapClient30Class = new MSOSOAPLib30.SoapClient30Class(); // Здесь возникает ошибка!
          
        }
    }
}