i want some date disable after select in datetimepicker

Question

{

DateTime lastDate;

System.Text.RegularExpressions.Regex rg;

bool valueChangingProgramatically = false;

public Form4()

{

InitializeComponent();

}

private void Form4_Load(object sender, EventArgs e)

{

dateTimePicker1.CustomFormat = "yyyy";

dateTimePicker1.Format = DateTimePickerFormat.Custom;

dateTimePicker2.MinDate = DateTime.Now.Date;

//Max Date will restrict the user to select future dates than the specified date

dateTimePicker2.MaxDate = DateTime.Now.AddDays(30).Date; ;

}

private void dateTimePicker2_ValueChanged(object sender, EventArgs e)

{

}

private void dateTimePicker3_ValueChanged(object sender, EventArgs e)

{

dateTimePicker3.ValueChanged += new EventHandler(dateTimePicker3_ValueChanged);

if (!valueChangingProgramatically)

{

if (rg.IsMatch(dateTimePicker3.Value.ToLongDateString()))

{

valueChangingProgramatically = true;

if (lastDate < dateTimePicker3.Value)

dateTimePicker3.Value = dateTimePicker3.Value.AddDays(1);

else

dateTimePicker3.Value = dateTimePicker3.Value.AddDays(-1);

}

}

else

valueChangingProgramatically = false;

lastDate = dateTimePicker3.Value;

}

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)

{

string fff = comboBox1.SelectedItem.ToString(); //not working

textBox1.Text = fff;

MessageBox.Show("ddddddddd", textBox1.Text);

lastDate = dateTimePicker3.Value;

rg = new System.Text.RegularExpressions.Regex(fff);

if (lastDate < dateTimePicker3.Value)

dateTimePicker3.Value = dateTimePicker3.Value.AddDays(1);

}