When customizing your GoldMine record layout, you can make any field "required". This means that the user will not be able to navigate away from the Contact Record until the field has been filled.
To do this;
1. Enter Customization Mode by right-clicking on the Contact Record and selecting "Screen Design".
2. Find and right-click on the field you'd like to make Required.
3. Select "Properties".
4. Go to the "Security" Tab.
5. Check the box which says "Required Data Entry".
"Ok" your way back out. Users may need to restart their GoldMine to get the new changes.