MyCalendarProgram(last edited at 5.9.09)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace myfun_1_
{
public partial class Form1 : Form
{
public int date;
public int month;
public int monthValue;
public int year;
public int yearValue;
public int ans1,ans2,ans3;
public DateTime kk;
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
date = Convert.ToInt32(comboBox1.Text);
month = Convert.ToInt32(comboBox2.Text);
year = Convert.ToInt32(comboBox3.Text);
if ((year > 1900) && (year < 1999))
{
yearValue = year - 1900;
switch (month)
{
case 1:
monthValue = 1;
break;
case 2:
monthValue = 4;
break;
case 3:
monthValue = 4;
break;
case 4:
monthValue = 0;
break;
case 5:
monthValue = 2;
break;
case 6:
monthValue = 5;
break;
case 7:
monthValue = 0;
break;
case 8:
monthValue = 3;
break;
case 9:
monthValue = 6;
break;
case 10:
monthValue = 1;
break;
case 11:
monthValue = 4;
break;
case 12:
monthValue = 6;
break;
}
}
else if ((year > 2000) && (year < 2099))
{
yearValue = year - 2000;
switch (month)
{
case 1:
monthValue = 0;
break;
case 2:
monthValue = 3;
break;
case 3:
monthValue = 3;
break;
case 4:
monthValue = 6;
break;
case 5:
monthValue = 1;
break;
case 6:
monthValue = 4;
break;
case 7:
monthValue = 6;
break;
case 8:
monthValue = 2;
break;
case 9:
monthValue = 5;
break;
case 10:
monthValue = 0;
break;
case 11:
monthValue = 3;
break;
case 12:
monthValue = 6;
break;
}
}
else
{
MessageBox.Show("Enter year between 1900-2099");
return;
}
ans1 = yearValue / 4;
ans2 = yearValue + ans1 + date + monthValue;
ans3 = ans2 % 7;
if ((yearValue % 4==0)&& ((month == 1) || (month == 2)))
{
ans3 = ans3 - 1;
}
switch (ans3)
{
case 1:
label7.Text= "Sunday";
break;
case 2:
label7.Text="Moneday";
break;
case 3:
label7.Text= "Tuesday";
break;
case 4:
label7.Text= "Wednesday";
break;
case 5:
label7.Text = "Thursday";
break;
case 6:
label7.Text="Friday";
break;
case 0:
label7.Text="Saturday";
break;
default:
break;
}
DateTime mydate = new DateTime(1990,month,date); //convert from integer to datetime





}


}
}