C#

public static class Alphabet {

   public static IEnumerator Lower() {
      for (char i = 'a'; i <= 'z'; i++) yield return i;
   }

   public static IEnumerator Upper() {
      for (char i = 'A'; i <= 'Z'; i++) yield return i;
   }

}

foreach (char i in Alphabet.Lower()) comboBox1.Items.Add(i);

Nitron wrote:

match a literal "$" as it's not a valid escape character...

Daniel Grunwald wrote:

So you'll have to use "\\$" or @"\$" in C#

private void toolStripButton1_Click(object sender, EventArgs e)
{
    toolStripButton2.Visible = true;
    toolStripTextBox1.Visible = true;
}

private void toolStripButton2_Click(object sender, EventArgs e)
{
    toolStripButton2.Visible = false;
    toolStripTextBox1.Visible = false;
}