ComboBox selection activate sub

Hi,

When the user makes a choice (selection) in the combobox he should activate a sub depending on his choice. How can I do this ?

  Sheet1.ComboBox1.AddItem "(All)"
  Sheet1.ComboBox1.AddItem "Actual "
  Sheet1.ComboBox1.AddItem "Actual Month"
  Sheet1.ComboBox1.AddItem "Actual Month Country"