[c#] MessageBox Buttons?

How would I say if the yes button on the messagebox was pressed do this,that and the other? In C#.

An updated version of the correct answer for .NET 4.5 would be.

if (MessageBox.Show("Are you sure?", "Confirm", MessageBoxImage.Question) 
    == MessageBoxResult.Yes)  
{
// If yes
}
else  
{
// If no
}

Additionally, if you wanted to bind the button to a command in a view model you could use the following. This is compatible with MvvmLite:

public RelayCommand ShowPopUpCommand
{
   get
   {
   return _showPopUpCommand ??
      (_showPopUpCommand = new RelayCommand(
         () =>
               {
                // Put if statement here
               }
      }));
   }
}

This way to check the condition while pressing 'YES' or 'NO' buttons in MessageBox window.

DialogResult d = MessageBox.Show("Are you sure ?", "Remove Panel", MessageBoxButtons.YesNo);
            if (d == DialogResult.Yes)
            {
                //Contents
            }
            else if (d == DialogResult.No)
            {
                //Contents
            }

If you actually want Yes and No buttons (and assuming WinForms):

void button_Click(object sender, EventArgs e)
{
    var message = "Yes or No?";
    var title = "Hey!";
    var result = MessageBox.Show(
        message,                  // the message to show
        title,                    // the title for the dialog box
        MessageBoxButtons.YesNo,  // show two buttons: Yes and No
        MessageBoxIcon.Question); // show a question mark icon

    // the following can be handled as if/else statements as well
    switch (result)
    {
    case DialogResult.Yes:   // Yes button pressed
        MessageBox.Show("You pressed Yes!");
        break;
    case DialogResult.No:    // No button pressed
        MessageBox.Show("You pressed No!");
        break;
    default:                 // Neither Yes nor No pressed (just in case)
        MessageBox.Show("What did you press?");
        break;
    }
}

Check this:

                     if (
 MessageBox.Show(@"Are you Alright?", @"My Message Box",MessageBoxButtons.YesNo) == DialogResult.Yes)
                    {
                        //YES ---> Ok IM ALRIGHHT
                    }
                    else
                   {
                   //NO --->NO IM STUCK
                    }

Regards

if(DialogResult.OK==MessageBox.Show("Do you Agree with me???"))
{
         //do stuff if yess
}
else
{
         //do stuff if No
}