I am getting an error "Unreachabl e code detected" when I add a switch statement.

My code looks like:

Code:
private void calbtn_click(object sender, EventArgs e)
{
  double regFee;
  double lodging;
  double days;
  string Total
  {
    string course;
    if (courselistbox.SelectedIndex !=-1)
      course=courselistbox.SelectedItem.ToString();
    switch (course)
...