OpenFileDialog choofdlog = new OpenFileDialog();
choofdlog.Filter = "All Files (*.*)|*.*";
choofdlog.FilterIndex = 1;
choofdlog.Multiselect = true;
if (choofdlog.ShowDialog() == DialogResult.OK)
{
string sFileName = choofdlog.FileName;
string[] arrAllFiles = choofdlog.FileNames; //used when Multiselect = true
}