copy a file and change the name : i was asked to make a file copier that will change the name of the file (add "_Copy") but will keep the type of file 
for example: 
c:\...mike.jpg(or mp3 or any type of file)
to:
c:\...mike_Copy.jpg

here is my code :

    private void btnChseFile_Click(object sender, EventArgs e)
        {
            prgrssBar.Minimum = 0;
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Title = "Which file do you want to copy ?";            
            
            DialogResult fc = ofd.ShowDialog();                       
            tbSource.Text = ofd.FileName;
            tbDestination.Text = tbSource.Text + "_Copy";
                       
        }            