VB Code:
  1. Private Sub TextBox1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
  2.         If e.KeyCode = 13 Then
  3.             ListBox1.Items.Add(TextBox1.Text)
  4.             TextBox1.Text = ""
  5.  
  6.         End If
  7.     End Sub