the search uses the space as an or seporator, so you search for
"by appointment only" becomes:
where (productName LIKE '%by%') OR (productName LIKE '%appointment%') OR (productName LIKE '%only%')
To change how that functions, find the following
$WADbSearch1->keywordComparison($KeyArr1,"".((isset($_GET["S_ProductName"]))?$_GET["S_ProductName"]:"") ."","AND","Includes",",%20","%20","%22","%22",0);
and change it to:
$WADbSearch1->keywordComparison($KeyArr1,"".((isset($_GET["S_ProductName"]))?$_GET["S_ProductName"]:"") ."","AND","Includes","AND%20","OR%20","%22","%22",0);
this will change the OR separator to "OR " so your search for
"by appointment only" becomes:
where (productName LIKE '%by appointment only%')