hi,
can any one suggest why the program 2 is not working.
only difference is

for ab in *.txt
for ab in a_DATA.txt b_DATA.txt c_DATA.txt
------------------------------------
Program :1 (working fine)

#!/bin/ksh

for ab in a_DATA.txt b_DATA.txt c_DATA.txt
suf="_"
echo "old->[${ab}] new->[${root}${suf}${_time}]"

old="${ab} "
new=${root}${suf}${_time}

cp $old $new

echo "$_time"
echo "$root"
echo "$new"
done

========================
Program :2 (Not working )

#!/bin/ksh

for ab in *.txt
suf="_"
echo "old->[${ab}] new->[${root}${suf}${_time}]"

old="${ab} "
new=${root}${suf}${_time}

cp $old $new

echo "$_time"
echo "$root"
echo "$new"
done

Thanks in advance !!

for starters for loops look like this:
Next, by "not working" - tell us what is the problem? What you gave us cannot possibly work without the "do"