Shell Programming and Scripting

Hi
I need help to write a script to do following:
Sample Input file1:
07-01-08 08:48:07:982 INFO [main] ....
07-01-08 08:49:07:982 DETAIL .....
07-01-08 08:50:14:982 INFO [main] .....
07-01-08 08:51:23:982 DETAIL .....
07-01-08 08:52:57:982 INFO [main] .....
07-01-08 08:53:01:982 DETAIL .....
07-01-09 01:53:01:982 DETAIL .....
07-01-10 16:00:00:000 INFO [main] .....

take the last date that contains 'DETAIL' word and then compare it with current time. If the difference is more than 30 minutes, then print 'Need Detail'


I can do it on the command line using:
grep DETAIL file1

and so far, i can convert the time to minutes using awk:
function to_sec(time){
split(time,a,":")
return (a[1]*60)+a[2]
}
{
print $2
request = to_sec($2)
currentTime = to_sec(date -s)
if ((currentTime - request) > 30)
{ print 'Need Detail' }
}

I am a newbie with script.. the above is totally not working.

Please help.
Thank you very much.

from the given input file...the below part of the script works as you desired.

lastdate=`date --date="$(grep "DETAIL" lastdate | tail -1 | cut -c 1-17)" +%s`
currdate=`date +%s`
diff=$(($currdate-$lastdate))
if [ $diff -gt "1800" ]
then
echo "It has been more than 30 mins, Need Details!"
fi


-ilan