mysql connection question

Hi, For a long time, on all of my mysql pages, I've done something like this $conn = mysql_connect($server,$username,$password) or die("Could not connect") mysql_select_db($db); I've finally put that into its own script file, moved it to my include files, and simply included it whereever I needed a connection. My question is, could this get me into trouble if multiple people access the database at the same time?