I have a type ahead text field, and when the user hits "Enter" I want to make an ajax call and not submit the form at the same time. My html looks like this:

```
<input id="drug_name" class="drugs_field" type="text" size="30" onkeypress="handleKeyPress(event,this.form); return false;" name="drug[name]" autocomplete="off"/>
<div id="drug_name_auto_complete" class="auto_complete" style="display: none;"/>
<script type="text/javascript">
  //<![CDATA[
  var drug_name_auto_completer = new Ajax.Autocompleter('drug_name', 'drug_name_auto_complete', '/sfc/pharmacy/auto_complete_for_drug_name', {})
  //]]>
</script>

```