Webapp search combine fields

[justasking506]

I'm trying to create a quick search for a webapp. They would like the one input field (e.g keyowords) to search across 3 of the webapp fields. Keywords, suburb and postcode. Is this possible? I can see how to insert the webapp search fields (all available fields in the webapp) but I'm not sure how I combine them so that there's 1 input box, that searches 3 fields. Can anyone help? I'll paste the code for the 3 fields that I need combined, if that helps at all.

Thanks.

	<form name="catcustomcontentform90116" method="post" onsubmit="return checkWholeForm90116(this)" action="/Default.aspx?CCID=3136&FID=21242&ExcludeBoolFalse=True&PageID={module_oid}">
	<table cellspacing="0" cellpadding="2" border="0" class="webform">
	<tbody>
	<tr>
	<td><label for="CAT_txtKeywords">Keywords</label><br />
	<input type="text" name="CAT_txtKeywords" id="CAT_txtKeywords" class="cat_textbox" maxlength="255" /></td>
	</tr>
	<tr>
	<td><label for="CAT_Custom_55809">Suburb</label><br />
	<input type="text" maxlength="255" name="CAT_Custom_55809" id="CAT_Custom_55809" class="cat_textbox" /></td>
	</tr>
	<tr>
	<td><label for="CAT_Custom_55810">Postcode</label><br />
	<input type="text" maxlength="255" name="CAT_Custom_55810" id="CAT_Custom_55810" class="cat_textbox" /></td>
	</tr>
	<tr>
	<td><input type="submit" class="cat_button" value="Search" /></td>
	</tr>
	</tbody>
	</table>
	</form>
	<script src="/CatalystScripts/ValidationFunctions.js" type="text/javascript"></script>
	<script type="text/javascript">function checkWholeForm90116(theForm){var why = "";if (why != ""){alert(why);return false;}return true;}</script>
	{module_webappsresults}