--- a/configure.in	2006-06-22 13:02:59.197841560 +0800
+++ b/configure.in	2006-06-22 12:48:59.000000000 +0800
@@ -55,7 +55,7 @@
 
 CFLAGS="$CFLAGS -funsigned-char -O2" 
 CXXFLAGS="$CXXFLAGS -funsigned-char -O2"
-if test $enable_debug = 'yes';then
+if test "x$enable_debug" = "xyes";then
         CFLAGS="$CFLAGS -O0 -g3 -Wall" 
         CXXFLAGS="$CXXFLAGS -O0 -g3 -Wall" 
 else