Is It possible to show tooltip on dropdown in asp.net

Question

In my web application, i have dropdowncheckboxes control but i am trying to show tooltip on selectbox items. Is is possible to do.

 

I am tried code:

.aspx:

<link rel="stylesheet" href="css/bootstrap-3.1.1.min.css" type="text/css" />
<link href="https://code.jquery.com/ui/1.10.4/themes/ui-lightness/jquery-ui.css" rel="stylesheet" />
<script src="https://code.jquery.com/jquery-1.10.2.js"></script>
<script src="https://code.jquery.com/ui/1.10.4/jquery-ui.js"></script> 
 <script>     
    $(function () {     
         $("#tooltip1").tooltip(); }); 
</script> 
<div class="tooltip1"> 
<asp:DropDownCheckBoxes ID="dropdown1" runat="server" UseSelectAllNode="true" UseButtons="true" 
OnSelectedIndexChanged="dropdown1_SelectedIndexChanged" AutoPostBack="true"> 
<Style SelectBoxWidth="200" DropDownBoxBoxWidth="200" DropDownBoxBoxHeight="130" /> 
<Texts SelectBoxCaption="" /> </asp:DropDownCheckBoxes> <asp:Label runat="server" ID="tooltip1"></asp:Label>

.CS:

protected void Page_Load(object sender, EventArgs e)
 {        
     tooltip1.Text = dropdown1.Texts.SelectBoxCaption;
 } 
protected void dropdown1_SelectedIndexChanged(object sender, EventArgs e) 
{ 
List<String> checkedList = new List<string>(); 
foreach (ListItem item in dropdown1.Items) 
{ 
if (item.Selected)
 {         
    checkedList.Add(item.Value); 
}
 }   
dropdown1.Texts.SelectBoxCaption = String.Join(",", checkedList.ToArray());
}

tooltip is not displayed can anyone tell me where i did mistake i don't know. Is there any events to display tooltip

Thank you