Fix two typos
diff --git a/build_pxe_boot.sh b/build_pxe_boot.sh
index 9d44949..4f59ed6 100755
--- a/build_pxe_boot.sh
+++ b/build_pxe_boot.sh
@@ -55,7 +55,7 @@
 fi
 cp -p $PXEDIR/vmlinuz-${KVER} $DEST_DIR/ubuntu
 if [ ! -r $PXEDIR/stack-initrd.gz ]; then
-    cd $PXEDIR
+    cd $OPWD
     sudo $PROGDIR/build_pxe_ramdisk.sh $PXEDIR/stack-initrd.gz
 fi
 cp -p $PXEDIR/stack-initrd.gz $DEST_DIR/ubuntu
diff --git a/make_image.sh b/make_image.sh
index 81dd97c..0d5074b 100755
--- a/make_image.sh
+++ b/make_image.sh
@@ -144,7 +144,7 @@
 if [ -n "$IMAGEONLY" ]; then
     # Build image from chroot
     sudo vmbuilder $HYPER ubuntu $ARGS \
-      --existing-chroot=$CHR \
+      --existing-chroot=$CHROOTDIR \
       --overwrite \
       --rootsize=$ROOTSIZE \
       --swapsize=$SWAPSIZE \