diff --git a/lib/functions.sh b/lib/functions.sh
index a1124ce..e3c3dd3 100644
--- a/lib/functions.sh
+++ b/lib/functions.sh
@@ -6,11 +6,21 @@
 #   containsElement ARRAY 'a' => 0
 containsElement () {
 	local -a 'arraykeys=("${!'"$1"'[@]}")'
-	for index in ${arraykeys[*]}; do 
-		current=$1"[$index]"
-		[[ "${!current}" == "$2" ]] && return 0; # found
-	done
-	return 1; # not found
+  if $(isArray $1); then
+	  for index in ${arraykeys[*]}; do 
+  		current=$1"[$index]"
+		  [[ "${!current}" == "$2" ]] && return 0; # found
+	  done
+	  return 1; # not found
+  else
+    >&2 echo "ERROR: $1 not an array!" 
+    return 2; # not an array
+  fi
+}
+
+isArray(){
+  [[ "$(declare -p $1 2> /dev/null)" =~ "declare -a" ]] && return 0; # is an array
+  return 1; # not an array
 }
 
 ##