diff --git a/check_framemd5.sh b/check_framemd5.sh
index 450d620..9476fc7 100644
--- a/check_framemd5.sh
+++ b/check_framemd5.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
   SCRIPT=$(basename "${0}")
- VERSION='2016-10-08'
+ VERSION='2016-10-09'
   AUTHOR='ffmprovisr'
      RED='\033[1;31m'
     BLUE='\033[1;34m'
@@ -37,17 +37,20 @@ EOF
     exit 0
 }
 
+unset input_file
+unset input_hash
+
 while getopts ":hi:m:" opt; do
   case "${opt}" in
     h) _output_help ;;
     i) input_file=$OPTARG ;;
     m) input_hash=$OPTARG ;;
-    *) echo -e "${RED}Error:${NC }bad option -${OPTARG}" ; _output_prompt ;;
     :) echo -e "${RED}Error:${NC} option -${OPTARG} requires an argument" ; _output_prompt ;;
+    *) echo -e "${RED}Error:${NC }bad option -${OPTARG}" ; _output_prompt ;;
   esac
 done
 
-[ -z "${@}" ] && _output_prompt
+[[ -z "${#}" || ! ${input_file} || ! ${input_hash} ]] && _output_prompt
 echo -e "${BLUE}Please wait...${NC}"
 unset md5_tmp
 if [[ $OSTYPE = "cygwin" ]]; then
@@ -56,7 +59,9 @@ else
   md5_tmp="${HOME}/$(basename ${input_hash}).tmp"
 fi
 $(ffmpeg -i ${input_file} -loglevel 0 -f framemd5 -an ${md5_tmp})
-[[ ! -f ${md5_tmp} ]] && _output_prompt
+[[ ! -f ${md5_tmp} ]] && { echo -e "${RED}Error:${NC} '${input_file}' is not a valid audio-visual file."; _output_prompt; }
+unset old_file
+unset tmp_file
 old_file=$(grep -v '^#' ${input_hash})
 tmp_file=$(grep -v '^#' ${md5_tmp})
 if [[ "${old_file}" = "${tmp_file}" ]]; then