periodically check abailability of website

test_website.sh

#!/bin/bash

WEBSITE="mybash.tk"
EMAIL="ihc.ru.test@gmail.com"
TIMER=60 #how often send emails in seconds
SLEEP_TIMER=10 # how often check availability of website
#dont change STATUS variable it's default value
STATUS=1


#PROGRAM VARIABLES
WORKTIMER=$TIMER
WORKSTATUS=$STATUS

while true; do
	DATEIS=`date +"%H:%M:%S"`
        echo -n $DATEIS " - "; echo -n "$WEBSITE - "
        RESPOND=`curl -LI -silence $WEBSITE | grep  HTTP | grep -c "200"`
        if [[ "$RESPOND" -eq "0" ]]; then
		if [[ $WORKSTATUS -eq "1" ]]; then
               		echo  -e "\e[1;41mERROR: not working\e[0m"
			echo "$WEBSITE not answer at $DATEIS" | mail -s "$WEBSITE wrong HTTP ANSWER" $EMAIL
			if [[ $? ]]; then
				echo -e "Email Has been sent to -\e[1;42m $EMAIL \e[0m";
			fi
			WORKSTATUS=0;
			WORKTIMER=$TIMER;
			echo "TIMER to next email: $((WORKTIMER))s"
		elif [[ $WORKTIMER -eq "0" ]]; then 
			 echo  -e "\e[1;41mERROR: not working\e[0m"
			echo "$WEBSITE not answer at $DATEIS" | mail -s "$WEBSITE wrong HTTP ANSWER" $EMAIL
			if [[ $? ]]; then
				echo -e "Email Has been sent to -\e[1;42m $EMAIL \e[0m";
			fi
			WORKTIMER=$TIMER;
		else
			WORKTIMER=$(( $WORKTIMER - $SLEEP_TIMER))
			echo  -e "\e[1;41m ERROR: still not working:\e[0m next email after "$WORKTIMER"s";
		fi

	else
		echo -e "\e[1;43m Working well\e[0m"
		WORKSTATUS=$STATUS
		WORKTIMER=$TIMER
		echo "Status :$WORKSTATUS TIMER: $WORKTIMER"
	fi
        sleep $SLEEP_TIMER ;
done

how it looks - http://scr.pics/d0c1702600b28.jpg
If website is not available, an email alert will be sending to administrator.
You can easy adjust a time how often send emails.