Need help with this program please!

LindaJ

Hello! I am working on the following assignment: Modify a program that I had already written to provide a method NextDay to increment the day by one. The cDateCheckChange object should always stay in the constant state. Then write a program that tests the NextDay method in a loop that prints the date during each iteration of the loop to illustrate that the NextDay method works correctly. Be sure to test the following cases: a)Incrementing into the next month b)Incrementing into the next year

I have pasted my code below. I know that in the cDateCheckChange class, everything except the NextDay method works fine, so that must be where my problem is. If you could please tell me what I have done wrong, I would really appreciate it! Thanks for your time and help!

Linda

Here is the cDateCheckChange class code:

Public Class cDateCheckChange
Inherits Object

Private mMonth As Integer ' 1-12
Private mDay As Integer ' 1-31 based on month
Private mYear As Integer ' any year

' constructor confirms proper value for month, then calls
' method CheckDay to confirm proper value for day
Public Sub New(ByVal monthValue As Integer, _
ByVal dayValue As Integer, ByVal yearValue As Integer)
Dim counter As Integer
counter = 0
' ensure month value is valid
If (monthValue > 0 AndAlso monthValue <= 12) Then
mMonth = monthValue
Else
mMonth = 1

' inform user of error
Dim errorMessage As String = _
"Month invalid. Set to month 1."

MessageBox.Show(errorMessage, "", _
MessageBoxButtons.OK, MessageBoxIcon.Error)
End If

mYear = yearValue
mDay = CheckDay(dayValue) ' validate day

While counter <> 10
NextDay(mYear, mDay, mMonth)
counter = counter + 1
End While

End Sub ' New

' confirm proper day value based on month and year
Private Function CheckDay(ByVal testDayValue As Integer) _
As Integer

Dim daysPerMonth() As Integer = _
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}

If (testDayValue > 0 AndAlso _
testDayValue <= daysPerMonth(mMonth)) Then

Return testDayValue
End If

' check for leap year in February
If (mMonth = 2 AndAlso testDayValue = 29 AndAlso _
mYear Mod 400 = 0 OrElse mYear Mod 4 = 0 AndAlso _
mYear Mod 100 <> 0) Then

Return testDayValue
Else

' inform user of error
Dim errorMessage As String = _
"day " & testDayValue & "invalid. Set to day 1. "

MessageBox.Show(errorMessage, "", _
MessageBoxButtons.OK, MessageBoxIcon.Error)

Return 1 ' leave object in consistent state
End If

End Function ' CheckDay

' create string containing month/day/year format
Public Function ToStandardString() As String
Return mMonth & "/" & mDay & "/" & mYear
End Function ' ToStandardString

Public Function NextDay(ByVal mDay As Integer, ByVal mMonth As Integer, ByVal mYear As Integer) As String

If mMonth = 1 AndAlso mDay = 32 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If (mMonth = 2 AndAlso mDay = 29 AndAlso mYear Mod 400 = 0 OrElse mYear Mod 4 = 0 AndAlso mYear Mod 100 <> 0) Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
ElseIf mMonth = 2 AndAlso mDay = 29 Then
mMonth += 1
mDay = 1
End If

If mMonth = 3 AndAlso mDay = 32 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 4 AndAlso mDay = 31 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 5 AndAlso mDay = 32 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 6 AndAlso mDay = 31 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 7 AndAlso mDay = 32 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 8 AndAlso mDay = 32 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 9 AndAlso mDay = 31 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 10 AndAlso mDay = 32 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 11 AndAlso mDay = 31 Then
mMonth += 1
mDay = 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

If mMonth = 12 AndAlso mDay = 31 Then
mMonth += 1
mDay = 1
mYear += 1
Return mMonth & "/" & mDay & "/" & mYear
Else
Return mMonth & "/" & mDay & "/" & mYear
End If

End Function


End Class

And here is the program code:
Public Class Form1
Inherits System.Windows.Forms.Form


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim dateChange As cDateCheckChange
Dim output As String

dateChange = New cDateCheckChange(Me.DayBox.Text, Me.MonthBox.Text, Me.YearBox.Text)
output = dateChange.ToStandardString

Me.outputBox.Text = output

End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.DayBox.Text = " "
Me.MonthBox.Text = " "
Me.YearBox.Text = " "
Me.outputBox.Text = " "

End Sub
End Class


Thanks Again!!!!