SSC Rookie was right after all. There was only 1 declare statement to many.

After I restarted MS SQL server Management Studio, it was working.

Thanks for the help.

Hmm, I'm not sure if this is what I'm looking for. Maybe my intention was not clear.

Where I'm looking for is a way to make a stored procedure for filling...

I tried your suggestion, but it made no difference 🙁