diff --git a/scripts/check_audio_framemd5.sh b/scripts/check_audio_framemd5.sh
index 27253ac..7b72fe3 100755
--- a/scripts/check_audio_framemd5.sh
+++ b/scripts/check_audio_framemd5.sh
@@ -1,19 +1,19 @@
 #!/usr/bin/env bash
   SCRIPT=$(basename "${0}")
- VERSION='2017-04-17'
+ VERSION='2017-07-08'
   AUTHOR='ffmprovisr'
      RED='\033[1;31m'
     BLUE='\033[1;34m'
       NC='\033[0m'
 
-if [[ ${OSTYPE} = "cygwin" ]] || [ ! $(which diff) ]; then
+if [[ "${OSTYPE}" = "cygwin" ]] || [ ! $(which diff) ]; then
     echo -e "${RED}Error: 'diff' is not installed by default. Please install 'diffutils' from Cygwin.${NC}"
     exit 1
 fi
 
 _output_prompt(){
     cat <<EOF
-Usage: ${SCRIPT} -h | -i <av_file> -m <md5_file>
+Usage: ${SCRIPT} -i <av_file> -m <md5_file> | -h
 EOF
     exit 1
 }
@@ -21,13 +21,11 @@ EOF
 _output_help(){
     cat <<EOF
 Syntax:
-  ${SCRIPT}
-    Prompts a short help message.
-  ${SCRIPT} -h
-    This help.
   ${SCRIPT} -i <av_file> -m <md5_file>
     Pass to the script the audio-visual file and the corresponding MD5
     file to check.
+  ${SCRIPT} -h
+    This help.
 Dependency:
   ffmpeg
 About:
@@ -40,11 +38,11 @@ EOF
 unset input_file
 unset input_hash
 
-while getopts ":hi:m:" opt; do
+while getopts ":i:m:h" opt; do
     case "${opt}" in
+        i) input_file=${OPTARG} ;;
+        m) input_hash=${OPTARG} ;;
         h) _output_help ;;
-        i) input_file=$OPTARG ;;
-        m) input_hash=$OPTARG ;;
         :) echo -e "${RED}Error: option -${OPTARG} requires an argument${NC}" ; _output_prompt ;;
         *) echo -e "${RED}Error: bad option -${OPTARG}${NC}" ; _output_prompt ;;
     esac
@@ -59,12 +57,12 @@ else
     md5_tmp="${HOME}/$(basename "${input_hash}").tmp"
 fi
 # Find audio frame size for hash calculation
+unset sample_rate
 sample_rate=$(grep -v '^#' "${input_hash}" | head -n 1 | tr -d ' ' | cut -d',' -f4)
 ffmpeg -i "${input_file}" -loglevel 0 -af "asetnsamples=n='$sample_rate'" -f framemd5 -vn "${md5_tmp}"
 [[ ! -f ${md5_tmp} ]] && { echo -e "${RED}Error: '${input_file}' is not a valid audio-visual file.${NC}" ; _output_prompt ; }
 unset old_file
 unset tmp_file
-unset sample_rate
 old_file=$(grep -v '^#' "${input_hash}")
 tmp_file=$(grep -v '^#' "${md5_tmp}")
 if [[ "${old_file}" = "${tmp_file}" ]]; then