Off topic:awk command in shell script

Question

[mittu1602]

I have an awk command which runs well on terminal: this awk command creates diffrent file according to their column header. awk command:

for((i=2;i<5;i++)); do awk -v i=$i 'BEGIN{OFS=FS="\t"}NR==1{n=$i}{print $1,$i > n".txt"}' ${Batch}.result.txt; done

the same command when incorporated in a shell script shows error:

Syntax error: Bad for loop variable