--- changer-src/chg-zd-mtx.sh.in.orig	Wed Feb  9 21:58:30 2005
+++ changer-src/chg-zd-mtx.sh.in	Wed Feb  9 21:58:49 2005
@@ -413,7 +413,7 @@
 
 IsNumeric() {
 	test -z "$1" && return 1
-	x="`expr "$1" : '\([-0-9][0-9]*\)' 2>/dev/null`"
+	x="`expr -- "$1" : "\([-0-9][0-9]*\)" 2>/dev/null`"
 	return `expr X"$1" != X"$x"`
 }