$dbconn = mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql');
mysql_select_db($dbname);
mysql_query("SET NAMES 'utf8'");

function getChallenge() {
	$query="SELECT * FROM challenges";
	$result = mysql_query($query);
	$row = mysql_fetch_array($result, MYSQL_ASSOC);

	/*
	Warning:  mysql_fetch_array(): supplied argument is not a valid MySQL result resource
	*/
}

$query="SELECT * FROM challenges";
$result = mysql_query($query);
$row = mysql_fetch_array($result, MYSQL_ASSOC);

//works fine