diff --git a/test.sh b/test.sh
index d289f72..1cf45ed 100755
--- a/test.sh
+++ b/test.sh
@@ -18,12 +18,13 @@ fi
 
 
 
-while getopts ':abcr' flag; do
+while getopts ':abcr:' flag; do
     case "${flag}" in
-        r) echo "R=${flag[r]}" ;;
-		a) echo "A=${flag[a]}" ;;
-		b) echo "B=${flag[b]}" ;;
-		c) echo "C=${flag[c]}" ;;
+        r) $flag=$OPTARG; echo "R=$r" ;;
+        a) $flag=$OPTARG; echo "A=$a" ;;
+        b) $flag=$OPTARG; echo "B=$b" ;;
+        c) $flag=$OPTARG; echo "C=$c" ;;
+   	 	:) echo "Invalid option: $OPTARG requires an argument" 1>&2 ;;
     esac
 done