Correct files for jQuery UI Autocomplete

Fairly new to jQuery, trying to use Autocomplete. Went to http://jqueryui.com/download to build my own download, selected "Autocomplete" from the "Widgets" section. This caused "Core", "Widget", and "Position" to auto-check.

I downloaded my custom jQuery UI, and followed the instructions and included the following in my page.

<link type="text/css" href="css/custom-theme/jquery-ui-1.8.7.custom.css" rel="stylesheet" />    
<script type="text/javascript" sr开发者_高级运维c="js/jquery-1.4.4.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.7.custom.min.js"></script>

But, Autocomplete would not function, and firebug revealed no errors. I decided to include:

<link rel="stylesheet" href="http://dev.jquery.com/view/trunk/plugins/autocomplete/jquery.autocomplete.css" type="text/css" />
<script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/autocomplete/lib/jquery.bgiframe.min.js"></script>
<script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/autocomplete/jquery.autocomplete.js"></script>

And everything started working! But I am confused, I thought the jQuery builder would have included all necessary code and styling for Autocomplete to function correctly, so why have I needed to add these extra includes to get it working? Thanks

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It appears you are using the autocomplete plugin, rather than the one from jQuery UI

See this question for the difference.