Please check for any errors. Let me know if i need to place commas anywhere or delete.

Attached are the Widget Sales figures for the past six months. My principle concern is the lack of effectiveness of the sales manager in the Southwest Division. The sales has drop in each of the last three quarters. During the same time period, sales in the other divisions have continued to increase. I recommend that we consider replacing the Southwest division sale manager. Patricia Miller salesperson in the Western Division has shown considerable promises. We might consider her as a possible replacement.
I also recommend that we discontinue production of the Widget 274B. Sales of this model have declined sharply in the past six years. Sales of the new digital Widget DW1 have exceeded our expectations. Santiago Zelaya in the research and development department informed me that they are almost ready to release the new Widget DW5 for production. We should discontinue the production of model 274B at least three months before we go into production of the new DW5.
The Central and Northern Divisions has been most effective in selling the Widget accessories. I suggest that we consider reviewing their advertising and sale technique to determine if they could be effectively applied in the other divisions.
May I have an appointment to discuss these recommendations with you?

Here is your corrected text with the necessary commas added and errors fixed:

"Attached are the Widget Sales figures for the past six months. My principal concern is the lack of effectiveness of the sales manager in the Southwest Division. The sales have dropped in each of the last three quarters. During the same time period, sales in the other divisions have continued to increase. I recommend that we consider replacing the Southwest division sales manager. Patricia Miller, a salesperson in the Western Division, has shown considerable promise. We might consider her as a possible replacement.

I also recommend that we discontinue production of the Widget 274B. Sales of this model have declined sharply in the past six years. Sales of the new digital Widget DW1 have exceeded our expectations. Santiago Zelaya in the research and development department informed me that they are almost ready to release the new Widget DW5 for production. We should discontinue the production of model 274B at least three months before we go into production of the new DW5.

The Central and Northern Divisions have been most effective in selling the Widget accessories. I suggest that we consider reviewing their advertising and sales techniques to determine if they could be effectively applied in the other divisions.

May I have an appointment to discuss these recommendations with you?"