title: Bind the textbox value with values in other controls
body: <p>I have a <code>textbox</code> whose text value I want to bind based on the values selected in two other controls.</p>
  
  <p>For example, I have a <code>ListBox</code> and I choose a value say "Blue" and one other <code>TextBox</code> whose text value is say a Name - "Sam".
  So I want my <code>TextBox.Text</code> value to be like "Blue_Sam".</p>
  
  <p>Is this possible?</p>