อยากทราบวิธีตรวจสอบวันที่ เพื่อเวลาบันทึกวันเกิดไม่ให้เกินวันที่ปัจจุบัน

DateTime date1 = new DateTime(2009, 8, 1, 0, 0, 0);
DateTime date2 = new DateTime(2009, 8, 1, 12, 0, 0);
int result = DateTime.Compare(date1, date2);
string relationship;

if (result < 0)
   relationship = "is earlier than";
else if (result == 0)
   relationship = "is the same time as";         
else
   relationship = "is later than";

Console.WriteLine("{0} {1} {2}", date1, relationship, date2);
// The example displays the following output:
//    8/1/2009 12:00:00 AM is earlier than 8/1/2009 12:00:00 PM

Dim date1 As Date = #08/01/2009 12:00AM#
Dim date2 As Date = #08/01/2009 12:00PM#
Dim result As Integer = DateTime.Compare(date1, date2)
Dim relationship As String

If result < 0 Then
   relationship = "is earlier than"
ElseIf result = 0 Then
   relationship = "is the same time as"         
Else
   relationship = "is later than"
End If

Console.WriteLine("{0} {1} {2}", date1, relationship, date2)
' The example displays the following output:
'    8/1/2009 12:00:00 AM is earlier than 8/1/2009 12:00:00 PM