title: How to count number of character which is entered in textbox?
body: <p>I have a label <code>lblCountCharacter</code> with text "4000" and a textbox <code>txtAddNote</code> where users can enter text. </p>
  
  <p>On entering one character in <code>txtAddNote</code>, the label text is decreased by one.</p>
  
  <p>Please help me write a function for this in asp.net using C#.</p>