Shell Programming and Scripting

bash-3.00# ./test.sh 100 10
./test.sh: syntax error at line 6: `(' unexpected
bash-3.00# cat test.sh
#!/bin/sh
start=0
end=$1
interval=$2
iostat -xnpr > disk_iostats.csv
for (( start=0; $start<=$end; start=$(($start+$interval)) ))
do
sleep $interval
iostat -xnpr | grep -v device >> disk_iostats.csv
done
bash-3.00#


Hello Experts, i'm stuck with some silly problme here with for, not sure where i'm doing wrong. can somebody point me my mistake in the above script?
:: two arguments i'm taking are end (which tels how many secs to run) and interval (which tells the interval of every run of iostat)


the above script runs fine on linux but not on solaris!?

Thanks for your time.