Trying to create a text input with an attached button

Everything you should need is this: See jsFiddle DEMO

<span class="k-textbox k-button k-space-right">
    <input value="This is the value" />
    <a class="k-icon k-filter"></a>
</span>

Also see the "documentation" (Look at the source for the example) for this here.

EDIT: Since the asker really wanted it to behave as a button (i.e. the click-effect), just add the k-button class to the outter span.