Best way to refer to javascript in UserControl(ascx)
<p>I usually create usercontrol which is referring javascript file/block. For example, I have a cascading Nation/City selection which is based on AJAX in my Register.ascx(a usercontrol), certainly I need add the javascript file into page. I have 3 ways at present:</p>

<p>1.Writing <code>&lt;Script&gt;</code> element in .ascx file directly, but it will bring nonstandard HTML structure due to many <code>&lt;Script&gt;</code> elements would appear in <code>&lt;Body&gt;</code>. </p>

<p>2.Writing <code>&lt;Script&gt;</code> element in aspx page which will use the usercontrol, but the father(aspx) rely on child(ascx), it's listening too bad.</p>

<p>3.Using <code>ScriptManager</code> or <code>HtmlGenericControl</code> to register file/block in head, but I'm worrying about performance of them, and it's a bit weird that I bring javascript to c# file.</p>
