Use a timer to make panel visible

Hello all,
 I am trying to use a timer on my asp.net page so that when a user clicks a button panel1 is shown for 10 seconds and then panel1 visible property is set to false and panel2 visible property set to true.  The code I have is as follows
private void methodcalledfrombuttonclick() {
panel1.Visible=truel
messagetimer.Interval=5000;messagetimer.Enabled=true; }
 
private void messagetimer_Elapsed(object< ...