calendar and onchange question

[Peter]

Hello

I'm a newbie a javascript so please help me out

I have a button that opens a calendar and populates a text box. I use
the onclick event to open the calendar.

Now the textbox has a onChange event that calls a function. The
onChange fires perfectly if I type the date on the textbox, but if the
calendar changes the date on the field then the onChange event doesn't fire.

I even try the following, but it seems that both functions run at the
same time and the value on the field is never picked up.

onclick="CalendarPicker('./calendar.aspx');setPen();
I was trying to get setPen to run after calendarpicker was done.

What do I need to do to get around this?

Thanks
Peter