Simple Upload File to Rapidshare Account Method using C#

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

namespace QUploadToRapidshare
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private string FilePath;
        private void button1_Click(object sender, EventArgs e)
        {
            openFileDialog1.ShowDialog();

        }

        private void openFileDialog1_FileOk(object sender, CancelEventArgs e)
        {
            FilePath = openFileDialog1.FileName;
            textBox1.Text = FilePath;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (textBox1.Text == "") openFileDialog1.ShowDialog();
            button2.Enabled = false;
            button2.Text = "Please Wait...";
            backgroundWorker1.RunWorkerAsync();
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            QRapidshare QRapid = new QRapidshare();
            int type = 0;//Free User
            if (radioButton1.Checked)
            {
                type = 1;//Premium User
            }
            else if (radioButton2.Checked)
            {
                type = 2;//Collector User
            }

            string result = QRapid.QUploadToRapidshare(FilePath, textBox2.Text, textBox3.Text, type);
            if (result.StartsWith("<!")) result = "Login failed!";
            e.Result = result;
        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            richTextBox1.Text = e.Result.ToString();
            button2.Enabled = true;
            button2.Text = "Upload";
        }

        private void textBox1_DoubleClick(object sender, EventArgs e)
        {
            openFileDialog1.ShowDialog();
        }





    }
}