Forums Scripts & Popups Have anybody any idea about this?

The return command can be used with a variable to return (hence the name) the value in the variable to a calling routine. This is the case if you have a script that calls an alias, then sends the results of that alias back to the main script.

The halt command, on the other hand, stops the processing of that script.
If you called an alias from the main script, and had a halt in the alias, then the entire script stops, not just the alias.