Combo Box linked to opening a form

hi,

Wondering if anyone can help me. I have a combo box which shows 5 different options. Each of these options has its own form. when the option is selected, I want the appropriate form to open.
Also, as this selection has been entered, I want an ID code to be entered into the database to show that "Option 3" has been selected.

Workflow:

"Option3" selected from drop down in Combo Box

This to open "Option3FORM"

As "Option3" is selected, I want an automated ID code to be entered (automatically) into "Option3ID" on the database.

I hope that makes sense. As my data is sensitive I am not able to send it over.

Thanks,

kathryn