how can call javascript function on button click in vb.net

<script type = 'text/javascript'>
function btnClick()
{
  if( divCalendar.style.display == "none")
    divCalendar.style.display = "block";
  else
    divCalendar.style.display = "none";
return false;
}
</script>

 

<asp:Button ID="Button2" runat="server"  Text="..." style="z-index: 100; left: 496px; position: absolute; top: 199px"  onClientClick = 'return btnClick()'/>