What is the best approach to show and hide an asp panel which is containing other controls like textbox and label controls
Can you try
document.getElementById( 'Panel1ClientId' ).style.display = 'none'; // to hide
and
document.getElementById( 'Panel1ClientId' ).style.display = 'block'; // to show
?
Using jQuery, you can just switch visibilty:
$('#<%= YourPanel.ClientID %>').hide();
$('#<%= YourPanel.ClientID %>').show();
Edit: jQuery is probably overkill just to hide/show, but if you plan to add more functionality client side, you should consider using it ;)