TextChanged Event do postback

Hi,
Got a custom control which is a datetimepicker. It is set of two
controls : textbox and button.
The button display a popup where user can select a date which is then
filled in the control textbox.

I just wanna know if it's possible to do postback for the page where
the custom control is when the popup fill the textbox ?

Thks for help.

.