This is the script i developed. pls help me in correcting it out as i am new to awk.

i =`iostat -dt | egrep -v "Linux|Device|Time" | cut -d" " -f1 |wc -l`i=`expr $i - 1`
j=$i
echo $i
echo "enter Iterations"
read iterations
echo "enter interval"
read interval
iostat -dt $interval $iterations | egrep -v "Linux|Device|Time" > file





for ((a=1;a<=$iterations;a++))
do
head -$i file | awk ' { s += $2 } { values["'$a'"]=s } END { print "Sum", values["'$a'"]}'
i=`expr $i + $j` done