title: asp.net C# get textbox lenght from code behind
body: <p>I would like to alert user about length of the mobile number which he has entered. </p>
  
  <p>my textbox ID : txt1</p>
  
  <p>my code behind :</p>
  
  <pre><code>if (txt1.txt.??? &lt; 11)
  {
  alert;;;
  }
  </code></pre>
  
  <p>please suggest me about tricks to perform this action.</p>
  
  <p>thanks in advance.</p>