Add value in publisher field

Can someone help me?

How do i add a value in a empty publisher filed for multiple files?

The publisher field is empty

In that filed i wanna add a record companie ex. "Warner"
Is it possible to add this value manually with a popup asking for a word to place in the publisher field?

Anyone have some ideas?
Or suggestions?

I recieve a lot of files from record companies and want to have this function, and it is a lot of files from different companies.

thx in advance

I'll give it a try:
There are several possibilities:

like this one: select the files without Publisher
Press Alt-T to open the extended Tags Dialogue.
Press the NEW button and select Publisher from the dropdown list (or enter the first couple of letters, the incremental search will complete the tag).
Enter the publisher name, press ok to close the "new" dialogue.
Then press OK to save the changes.

or this one:
Open Menu Tools>Options and scroll down to "tag-panel".
On the right press the the NEW button and enter publisher as new field to be displayed in the tag panel.
Close the Options dialogue.
You will now see a Publisher entry box in the tag panel.
Select the files without publisher, enter the publisher's name in the tag panel's field, press Ctrl-S to save the changes.

And thirdly you can add a column in the files list ...

THX for your time and knowledge. It was very helpful and will save me time in the future.