Make this work on Xorg

ppsh

@@ -15,7 +15,7 @@ generate_name() {
 }
 
 capture() {
-  if [ -n WAYLAND_DISPLAY ]; then
+  if [ -n "$WAYLAND_DISPLAY" ]; then
     slurp | grim -g - "$1"
   else
     maim -suk "$1"
@@ -23,7 +23,7 @@ capture() {
 }
 
 clipboard() {
-  if [ -n WAYLAND_DISPLAY ]; then
+  if [ -n "$WAYLAND_DISPLAY" ]; then
     wl-copy "$1"
   else
     echo "$1" | xsel -b