Pass parameters from a windows form to web service in C#

 private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                string productname = "All", FromDate = dateTimePicker1.Text, Todate = dateTimePicker2.Text, IN02 = "All", IN01 = "All", IN04 = "All", Type = "All";
                if (txt_product.Text.Trim() != "")
                {
                   productname = txt_product.Text.Trim();
                }
                if (ddl_pa.SelectedValue.ToString().Trim() != "")
                {
                    IN02 = ddl_pa.SelectedValue.ToString().Trim();
                }
                if (ddl_Pr.SelectedValue.ToString().Trim() != "")
                {
                    IN01 = ddl_Pr.SelectedValue.ToString().Trim();
                }
                if (txt_batn.Text.Trim() != "")
                {
                    IN04 = txt_batn.Text.Trim();
                }
                if (ddl_Type.SelectedValue.ToString().Trim() != "")
                {
                   Type = ddl_Type.SelectedValue.ToString().Trim();
                }
                productdata.product  productservice = new productdata.product();
//here I need to call the the web method and pass parameters
}
 catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

[WebMethod]
  public DataSet GetData(string productname, string FromDate, string Todate, string IN02, string IN01, string IN04, string Type)
    {
        DataSet ds = objcon.GetDataSet("exec SP0128");
        return ds;

    }