title: Detect if TextBox control's text has changed without the event handler
body: <p>I know that there is an event handler <code>TextChanged</code> that fires when a TextBox control's text has been changed but I am wondering if there is another way to detect if a TextBox has had it's value changed?</p>
  
  <p>I read that you can do something like store the initial value of the TextBox in the html tag but there was no detail on how to do that. Then apparently you can compare the initial value of the TextBox to it's current value and then run some code.</p>