textchanged event not firing

Hi,

I have a page which has a formview. In the edit and insert templates i have a usercontrol. This usercontrol has a textbox
with a datepicker. I need to access the textchanged event of the textbox, so i can get the new value entered in and enable
a validator based on this. I could do this on the usercontrol that contains the textbox. How do i do this?
I've tried to set autopostback on the textbox to true and create an event as follows, but the event is never fired.

protected void DateTextBox_TextChanged(object sender, EventArgs e)
        {
            
                if (MyDate.HasValue)
                {
           &nbs ...