Your
<input>
has
runat="server"
, but your
<form>
does not.
Either your page will return an exception indicating that the control must be placed inside a form tag with
runat="server"
; or the
<form>
tag you've shown is nested inside an existing server form.
Nested forms are not valid or supported. Their behaviour is undefined; they might
sort-of work in some browsers, but that is subject to change at any time.
Note: It's strictly forbidden to nest a form inside another form. Nesting can cause forms to behave in an unpredictable manner based on the browser that is being used.