[Charter]

In test.htm find:

<form action="http://www.aboutautism.org.uk/phpDig/search.php" target="search.htm" method="post">
<input type="text" name="query_string" value="">
<input type="submit" name="search" value="Go">
</form>

And replace with:

<script language="JavaScript">
function setCookie(name1, name2, expires, path, domain, secure) {
        var querynam = 'query_string';
        var queryval = document.forms[name1].elements[name2].value;
        document.cookie= querynam + "=" + escape(queryval) +
        ((expires) ? "; expires=" + expires.toGMTString() : "") +
        ((path) ? "; path=" + path : "") +
        ((domain) ? "; domain=" + domain : "") +
        ((secure) ? "; secure" : "");
}
</script>

<form name="query_form" action="search.htm" method="post" onsubmit="setCookie('query_form','query_string')">
<input type="text" name="query_string" value="">
<input type="submit" name="search" value="Go">
</form>

In search.php find:

if (ALLOW_RSS_FEED) {

And beforehand add:

if (strlen($query_string) == 0 && isset($_COOKIE['query_string'])) {
	if (strlen($_COOKIE['query_string']) > 0) {
		$query_string = $_COOKIE['query_string'];
		$_COOKIE['query_string'] = '';
	}
}

Keep the IFRAME in search.htm and see if these changes work.

If these changes don't work, the above may need tweaking or you can make a template like those in the templates folder.