title: I need masked textbox in asp.net
body: <ul>
  <li>only numbers must be in that textbox</li>
  <li>that entries have to be in 100 between 500</li>
  <li>TextBox Needed to include 3 Decimal Places</li>
  </ul>
  
  <p>I don't want any mistakes while values inserting to database.</p>
  
  <p>Do I need to use jQuery or ASP.NET Validation Controls?</p>
  
  <p>If jQuery is the useful one, then which plugin will I use? Or if it is asp.net RegEx Validator, which Validation Expression will I use?
  Or is there any free ASP.NET Extended TextBox ?</p>