Automatic postback does not fire for TextBox control

I recently come across an interesting request which read like this:A simple webapplication with one Textbox and one label. The Textbox has Autopostback=”true” and has an event listener attached to the TextChanged event. In the TextChanged event the label’s text is set to the text in the textbox. A javascript function “formats” the value of the textbox on the keyUp event.   The ”problem” The