How to Print Invoice using C#?

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace PrintInvoice
{
	/// <summary>
	/// Summary description for frmInput.
	/// </summary>
	public class frmInput : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Button btnOk;
		private System.Windows.Forms.Button btnCancel;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.TextBox txtOrder;
		private System.ComponentModel.Container components = null;

		public static string InvoiceOrder;

		public frmInput()
		{
			InitializeComponent();
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.btnOk = new System.Windows.Forms.Button();
			this.btnCancel = new System.Windows.Forms.Button();
			this.label1 = new System.Windows.Forms.Label();
			this.txtOrder = new System.Windows.Forms.TextBox();
			this.SuspendLayout();
			// 
			// btnOk
			// 
			this.btnOk.Location = new System.Drawing.Point(24, 64);
			this.btnOk.Name = "btnOk";
			this.btnOk.TabIndex = 0;
			this.btnOk.Text = "OK";
			this.btnOk.Click += new System.EventHandler(this.btnOk_Click);
			// 
			// btnCancel
			// 
			this.btnCancel.Location = new System.Drawing.Point(112, 64);
			this.btnCancel.Name = "btnCancel";
			this.btnCancel.TabIndex = 1;
			this.btnCancel.Text = "Cancel";
			this.btnCancel.Click += new System.EventHandler(this.btnCancel_Click);
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(24, 24);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(72, 20);
			this.label1.TabIndex = 2;
			this.label1.Text = "Enter Order:";
			// 
			// txtOrder
			// 
			this.txtOrder.Location = new System.Drawing.Point(104, 24);
			this.txtOrder.Name = "txtOrder";
			this.txtOrder.Size = new System.Drawing.Size(80, 20);
			this.txtOrder.TabIndex = 0;
			this.txtOrder.Text = "";
			// 
			// frmInput
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(202, 103);
			this.Controls.Add(this.txtOrder);
			this.Controls.Add(this.label1);
			this.Controls.Add(this.btnCancel);
			this.Controls.Add(this.btnOk);
			this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
			this.MaximizeBox = false;
			this.MinimizeBox = false;
			this.Name = "frmInput";
			this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
			this.Text = "Input Order";
			this.Load += new System.EventHandler(this.frmInput_Load);
			this.ResumeLayout(false);

		}
		#endregion

		private void btnOk_Click(object sender, System.EventArgs e)
		{
			InvoiceOrder = txtOrder.Text;
			this.Close();
		}

		private void btnCancel_Click(object sender, System.EventArgs e)
		{
			this.Close();
		}

		private void frmInput_Load(object sender, System.EventArgs e)
		{
			InvoiceOrder = "";
		}
	}
}