My keygen

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

namespace @interface
{
    public partial class frmkeygen : Form
    {
        public frmkeygen()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string com = textBox1.Text;
            string code = (Math.Abs((com.GetHashCode() + 5) * 5)).ToString();
            textBox2.Text = code;
        }
    }
}

namespace @interface
{
    partial class frmkeygen
    {
        /// <summary>
        /// 設計工具所需的變數。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// 清除任何使用中的資源。
        /// </summary>
        /// <param name="disposing">如果應該公開 Managed 資源則為 true，否則為 false。</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form 設計工具產生的程式碼

        /// <summary>
        /// 此為設計工具支援所需的方法 - 請勿使用程式碼編輯器修改這個方法的內容。
        ///
        /// </summary>
        private void InitializeComponent()
        {
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.textBox2 = new System.Windows.Forms.TextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            this.button1 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            //
            // textBox1
            //
            this.textBox1.Location = new System.Drawing.Point(72, 12);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(200, 22);
            this.textBox1.TabIndex = 0;
            //
            // textBox2
            //
            this.textBox2.Location = new System.Drawing.Point(72, 58);
            this.textBox2.Name = "textBox2";
            this.textBox2.Size = new System.Drawing.Size(100, 22);
            this.textBox2.TabIndex = 1;
            //
            // label1
            //
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(13, 13);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(53, 12);
            this.label1.TabIndex = 2;
            this.label1.Text = "公司名稱";
            //
            // label2
            //
            this.label2.AutoSize = true;
            this.label2.Location = new System.Drawing.Point(13, 61);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(29, 12);
            this.label2.TabIndex = 3;
            this.label2.Text = "序號";
            //
            // button1
            //
            this.button1.Location = new System.Drawing.Point(197, 56);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 4;
            this.button1.Text = "產生序號";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            //
            // Form1
            //
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(284, 100);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.textBox2);
            this.Controls.Add(this.textBox1);
            this.Name = "Form1";
            this.Text = "序號產生器";
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.TextBox textBox2;
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Label label2;
        private System.Windows.Forms.Button button1;
    }
}

         public Boolean DTS_authorize(string com, string code)
        {
            Boolean result = false;
            if (Math.Abs((com.GetHashCode() + 5) * 5) == int.Parse(code))
                result = true;
            return result;
        }