Fatal error: Call to undefined function: themeheader() in /membri/dedozzo/header.php on line 47

44- echo "<LINK REL=\"StyleSheet\" HREF=\"themes/$ThemeSel/style/style.css\" TYPE=\"text/css\">\n\n\n";
45- include("includes/my_header.php");
46- echo "\n\n\n</head>\n\n";
47- themeheader();
48- }


Che devo fare??!?! HELP!