$banner_table = $prefix.'banner';
$client_table = $prefix.'faclient';


$Query = "SELECT $banner_table.startdate
		, $banner_table.enddate
		, $banner_table.clicks
		, $banner_table.maxclicks
		, $banner_table.clientid
		, $client_table.clientid AS CID
		, $client_table.contactname
		, $client_table.contactemail	
	FROM $banner_table, $client_table
  INNER
	JOIN $client_table
	  ON $client_table.clientid = $banner_table.clientid";

$result = mysql_query($Query);
echo '<pre>';
echo print_r($Query);
echo '</pre>';

echo var_dump($result);

SELECT startdate.jos_banner
		, jos_banner.enddate
		, jos_banner.clicks
		, jos_banner.maxclicks
		, jos_banner.clientid
		, jos_faclient.clientid AS CID
		, jos_faclient.contactname
		, jos_faclient.contactemail	
	FROM jos_banner, jos_faclient
  INNER
	JOIN jos_faclient
	  ON jos_faclient.clientid = jos_banner.clientid1

bool(false)

$Query = "SELECT $banner_table.startdate
      , $banner_table.enddate
      , $banner_table.clicks
      , $banner_table.maxclicks
      , $banner_table.clientid
      , $client_table.clientid AS CID
      , $client_table.contactname
      , $client_table.contactemail   
   FROM $banner_table
  INNER
   JOIN $client_table
     ON $client_table.clientid = $banner_table.clientid";