• The system, by default, will associate the salesperson to the order based on the salesperson that has that customer assigned and whether Fresh Cut or Plants are being sold. 
• If the Salesperson Code setting is enabled and the salesperson has a code set up, under the Add Prebook screen, the field for Salesperson Code will appear to select a code from. Also, if under the settings there is a code selected as Default, the system will automatically default to that specific code. For more information on how to setup a Salesperson Code, please read the following article: Setup Company Users & User Options.
• The salesperson logged into Komet Sales who is entering the order is assigned as the salesperson as long as the Associate the logged user as salesperson setting is enabled within Setup > Settings > Prebook Settings. 
• The user is allowed to override the salesperson that was entered previously on the Prebook by changing the Salesperson field; if the Allow salespeople to change the salesperson of the ordersetting is enabled within Setup > Settings > Prebook Settings.
• Mark codes can be added as soon as the product line has been added to the Prebook.

Each location will have the option to enable or disable these settings to override the salesperson. For details on how to please review:

Single Location: Prebook Settings

Multi-Location: Prebook Settings - Multiple Locations