PHP mysql charset utf8 problems

I'm developing some new features on a website that somebody else already developed.

I'm having a problem the charset.

I saw that the database had some tables in utf8 and some in latin1

So I'm trying to convert all the tables in UTF8.

I did it for one table (also the fields of this table now are utf8), but was not successful.

I'm using the normal mysql connect. I have to put any config to say that it must connect with utf8 to the DB? If yes witch one?

In my html I have:

It looks like some letters works and others display the question mark.
For example it not able to display this ’ that is different of this: '

Answer

Try this

   header('Content-Type: text/html; charset=utf-8');

?>

and then in the connection

 $dbLink = mysql_connect($argHost, $argUsername, $argPassword);
    mysql_query("SET character_set_results=utf8", $dbLink);
    mb_language('uni'); 
    mb_internal_encoding('UTF-8');

    mysql_select_db($argDB, $dbLink);
    mysql_query("set names 'utf8'",$dbLink);
?>