Index: trunk/admin/include/mainscript.php
===================================================================
diff -u -N -r1611 -r2308
--- trunk/admin/include/mainscript.php	(.../mainscript.php)	(revision 1611)
+++ trunk/admin/include/mainscript.php	(.../mainscript.php)	(revision 2308)
@@ -285,7 +285,7 @@
 function ValidThemeName(name_str)
 {
 	if (trim(name_str) == '') return false;
-	var re = new RegExp('^[a-zA-Z0-9 ]{1,}$');
+	var re = new RegExp('^[a-zA-Z0-9-_]{1,}$');
 	if (name_str.match(re)) {
 		return true;
 	}