How do the words in the search append as in Google

I write "video " and I is added to the drop-down list:

video co开发者_高级运维nverter  
video saver 
video player

Ho do this? I just know that every time the asp.net page reloads, but I need without overloading.

You need to use a Autocomplete script. Microsoft's AJAX Control Toolkit provides that.

And there's also a jQuery UI Autocomplete.

Here are some tutorials on the subject:

Microsoft's:

• http://www.ajaxtutorials.com/ajax-tutorials/using-autocomplete-in-the-ajax-toolkit/
• http://www.ajaxtutorials.com/ajax-control-toolkit-tutorials/ajax-control-toolkit-tutorial-autocomplete-extender-using-asp-net-c/

jQuery's

• jQuery Autocomplete and ASP.NET
• JQuery AutoComplete plugin in ASP.Net page with C#

I will have the decency of not copying the code from those to here :)

You are talking about something called AutoComplete. To implement this functionality you will need to use AJAX. In ASP.NET there are two popular ways to accomplish this:

• The AJAX toolkit from Microsoft

• jQuery

I personally prefer jQuery because it feels more lightweight/intuitive than what Microsoft offers, but I would recommend looking at both and seeing what you are more comfortable with. The AJAX toolkit is more integrated with Visual Studio so many people prefer using this...