after inserting some script the dollar sign returns null
<p>javascript newbie here, I wrote a form in html and submitted it with an onchange event, but after I added a daterange picker in javascript the submission doesn't work. Here is my code:</p>

<pre><code>    &lt;form id="dash_form" method="get"&gt;
        &lt;div&gt;Select a Tag Bundle dimension:&lt;/div&gt;
        &lt;select name="dimension" id="id_dimension" onchange="$('form#dash_form').submit()"&gt;
            &lt;option value=""&gt;No dimension &lt;/option&gt;
            &lt;option value="Hello"&gt;Hello&lt;/option&gt;
        &lt;/select&gt;
        &lt;h4&gt;Please select a date range below:&lt;/h4&gt;
        &lt;div id="calendars"&gt;&lt;/div&gt;
        &lt;span&gt;
        &lt;input type="text" name="from" value="" id="start"/&gt;
        &amp;ndash;
        &lt;input type="text" name="to" value="" id="end"/&gt;
        &lt;/span&gt;
    &lt;/form&gt;
    &lt;script type="text/javascript" charset="utf-8" src="/site_media/crm/javascripts/prototype.js"&gt;&lt;/script&gt;
    &lt;script type="text/javascript" charset="utf-8" src="/site_media/crm/javascripts/timeframe.js"&gt;&lt;/script&gt;
    &lt;script type="text/javascript" charset="utf-8"&gt;
      //&lt;![CDATA[
        new Timeframe('calendars', {
          startField: 'from',
          endField: 'to',
          latest: Date.parseToObject({{Now}}),
          resetButton: 'reset' });
      //]]&gt;
    &lt;/script&gt;
</code></pre>

<p>in firebug I get <code>$("form#dash_form") is null</code>, and when I remove the script lines it works... what can cause this?</p>
