How to make an ASP.NET TextBox fire it's onTextChanged event fire in an AJAX UpdatePanel?

Question

I am trying to get an textBox to fire it\'s onTextChanged event every time a keystroke is made rather than only firing only when it loses focus. I thought that adding the As

Answer 1

AutoPostBack="true" OnTextChanged="TextBox1_TextChanged"

Both events are required to trigger text change event.