Automatically entering data in a field based on another field's data
Pardon my bad coice of words, I'm usually better with lingo and stuff, but I was curious if someone was able to help me with a question I have regarding entering data in fields.
One of the fields in my database of students in a school is a drop down menu with about 15 different options in it (for their teacher's name). I also have another field where I would like to include thir teacher's room number in the school. Since I am dealing with over 400 students, I relly don't want to type out a room number for each record, therefore, I was wondering if it is possible to make a room number automatically appear in the "Room Number" field when selecting the appropriate teacher.
For example: If Miss Jones teaches in room number 36.
Selecting "Miss Jones" in the "teacher" drop down menu would automatically make "Room 36" appear in the "Room Number" field.
Is this possible?
PS: I already have about 300 records entered, so creating the field, then going back to enter the data in to each one wouldn't be an option for me due to time contraints.