Visual Basic

Private Function GetDaysInMonth(ByVal year As Integer, ByVal month As Integer, ByVal day As System.DayOfWeek) As Integer
    'Date object for the first day of the month
    Dim myDate As New Date(year, month, 1)

    'Number of Days from the start of the month until the day
    'we are looking for.
    Dim nextOccurance As Integer = day - myDate.DayOfWeek
    If nextOccurance < 0 Then nextOccurance += 7

    'Return number of occurances in month
    Return Math.Ceiling((Date.DaysInMonth(year, month) - nextOccurance) / 7)
End Function

'Sundays in march 2007
Dim occurences = GetDaysInMonth(2007, 3, DayOfWeek.Sunday)

<code>
' Handle the KeyDown event to determine the type of character entered into the control.
Private Sub textBox1_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) _
         Handles textBox1.KeyDown
      
        ' Determine whether the keystroke is a number from the top of the keyboard.
        If e.KeyCode = 13 Then
           Call DoMyTask() ' That must be your procedure or function
        End If
    End Sub 

</code>