This question has already been answered:
I do this thing:
$time = time(); $online = $time - (20*60); $result = mysql_query("SELECT username FROM users WHERE users_come >= $online"); while( $row = mysql_fetch_array( $result ) ){ echo "<br>{$row['username']}"; } It displays users on-line, but I get the following error:
Warning: mysql_fetch_array () expects parameter 1 to be resource, given in C: xampphtdocsstyleonline.php on line 20
What does it mean and how to fix it please tell me!