title: Force ASP.NET textbox to display currency with $ sign
body: <p>Is there a way to get an ASP.NET textbox to accept only currency values, and when the control is validated, insert a $ sign beforehand?</p>
  
  <p>Examples:  </p>
  
  <p>10.23 becomes $10.23<br>
  $1.45 stays $1.45<br>
  10.a raises error due to not being a valid number  </p>
  
  <p>I have a RegularExpressionValidator that is verifying the number is valid, but I don't know how to force the $ sign into the text.  I suspect JavaScript might work, but was wondering if there was another way to do this.</p>