SAMPLE CODE: CUSTOM DIALOG [WINFORM] Project : VSS 2008.Net Framework : 2.0Language :

//Master form
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 CustomDialoque
{
    public partial class MasterForm : Form
    {
        public MasterForm()
        {
            InitializeComponent();
        }

        private void toolStripButtonCallDiloque_Click(object sender, EventArgs e)
        {
            DialogResult result = (new myDialoque()).ShowDialog(this);

            //Put your code within below condition
            if (result == System.Windows.Forms.DialogResult.OK)
                MessageBox.Show("Dialoque return 'OK'");
            else
                MessageBox.Show("ELSE"); 
        }       
    }
}

//Dialoque form
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 CustomDialoque
{
    public partial class myDialoque : Form
    {
        public myDialoque()
        {
            InitializeComponent();

            InitNeccessaryCustomDialoque();
        }


        void InitNeccessaryCustomDialoque()
        {
            //Can be set via property windows
            this.AcceptButton = myOkButton;
            this.CancelButton = myCancelButton;

            myOkButton.DialogResult = System.Windows.Forms.DialogResult.OK;
            myCancelButton.DialogResult = System.Windows.Forms.DialogResult.Cancel;

            this.StartPosition = FormStartPosition.CenterParent;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
            this.MaximizeBox = false;
            this.MinimizeBox = false;
        }
    }
}