General :: Export Is Not Working On Command Prompt?

The command export is working inside a shell script, but when I type it at the command prompt / terminal it doesn't work. "export: The command not found" error is displayed instead.

I tried this:

cat test.sh

Code:

abc=123
export abc
echo "Exit status of export abc: $?"

[code]....

I tried it before on my RHEL system and it was working. I have checked

Code:

echo $PATH

which is okay. What could be the problem?