is_resource
    (PHP 4 )
is_resource -- 
     Finds whether a variable is a resource
    
Description
bool 
is_resource ( mixed var)
     is_resource() returns TRUE if the variable
     given by the var parameter is a 
     resource, otherwise it returns FALSE.
    
     
Example 1. using is_resource() <?php
$db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
if (!is_resource($db_link)) {
    die('Can\'t connect : ' . mysql_error());
}
?> |  
  | 
    
     See the documentation on the resource-type for
     more information.