How to avoid flickering page while using JQuery Searchable Dropdown list in ASP.NET

Question

I am using ASP.NET dropdown controls and using JQuery for Searchable dropdown list.

When i click the dropdown it's allowing to enter text in the dropdown list.

But, after selecting the text, the whole page got flickering. I feel it is not good for end user.

How to maintain ASP.NET searchable dropdown without JQUERY or without flickering the page.

below is the code.

<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/themes/base/jquery-ui.css"  
        rel="stylesheet" type="text/css" />  
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>  
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/jquery-ui.min.js"></script>  
    <script src="Scripts/jquery.searchabledropdown-1.0.8.min.js" type="text/javascript"></script>  
    <script type="text/javascript">  
        $(document).ready(function () {  
            $("select").searchable({  
                maxListSize: 200, // if list size are less than maxListSize, show them all  
                maxMultiMatch: 300, // how many matching entries should be displayed  
                exactMatch: false, // Exact matching on search  
                wildcards: true, // Support for wildcard characters (*, ?)  
                ignoreCase: true, // Ignore case sensitivity  
                latency: 200, // how many millis to wait until starting search  
                warnMultiMatch: 'top {0} matches ...',  
                warnNoMatch: 'no matches ...',  
                zIndex: '-1'  
            });  
        });  
  
    </script>  

 

 <asp:DropDownList ID="ddlEmpNo" runat="server"   
                            AutoPostBack="true" >  
                            <asp:ListItem Selected="True" Text="<--Select-->" Value="0"></asp:ListItem>  
                        </asp:DropDownList>