C#

string message = "Snouto : " + textBox1.Text;
richTextBox1.Text += message + "\r\n";
int pos = 0;
int prevIndex = -1;
while(pos < richTextBox1.TextLength)
{
int index = richTextBox1.Find(textBox1.Text,pos,RichTextBoxFinds.None);
if(index == -1)
break;
prevIndex = index;
pos = index + RichTextBox1.TextLength;
}
index = prevIndex;
richTextBox1.Select(index,textBox1.Text.Length);
richTextBox1.SelectionFont = fontDialog1.Font;
richTextBox1.SelectionColor = colorDialog1.Color;

textBox1.Clear();

abstract class MyFormBase
{
   public abstract TextBox MyTextBox
   {
      get ;
   }
}

class MyForm : MyFormBase
{
   private TextBox textbox = new TextBox();
   public override TextBox MyTextBox
   {
       get { return textbox; }
   }
}

if (something)
{
rbNew = new RadioButton();
}