How to determine current MySQL link identifier?

Is there a function that returns the current MySQL link identifier? Many of the PHP MySQL functions allow you to leave out the link identifier parameter, in which case they use the default (current) connection. If I write a function, what's the best way to emulate this behavior? I guess one way would be to put every MySQL call inside the function in an if-statement. For example: function do_query ($query, $link_id = some_illegal_value) { if ($link_id != some_illegal_value) $result = mysql_query ($query, $link_id) else $result = mysql_query ($query) } But that seems silly and inefficient. Or is there some default value I can use for $link_id that I can pass to the MySQL functions to cause them to use the default connection? -- Paul DuBois, paul@snake.net