One way to Hide/Show information without postback

This is a simple method of hiding or showing information based on a users action. It utilizes CSS, Javascript, and ASP.NET controls

1.) Define CSS for .visible and .hidden 
.visible
{
    visibility: visible;
    position: relative;
}
.hidden
{
    visibility: hidden;
    position: absolute;
} 

2.) Create separation of content using divs and set onchange event

<div>
    Do you want to show more info?
    <asp:dropdownlist  id="Question" onchange="javascript:HideShow(this, 'Detail')" runat="server">            
        <asp:listitem> </asp:listitem>
        <asp:listitem value="True">Yes</asp:listitem>
        <asp:listitem value="False">No</asp:listitem>
    </asp:dropdownlist>     </div>
<div id="Detail">
    Some additional information

</div>

 3.) Set onclick method to hide/show inline or via Javascript function call 



    HideShow(var ctl, var detailsSection){
        if (document.getElementById)
        {
            var e = document.getElementById(detailsSection);
             if (e != null)
            {
                 e.className = (ctl.selectedIndex != 1 ? 'hidden' : 'visible');
            }
         }
    }