The Field Type option for a user-defined field cannot be changed after the field has been created. It is important to know ahead of time what kind of data you would like to enter into a field. To change the Field Type, you must inactivate the field and create a new one.
- Open the field and uncheck the Active checkbox
- Change the display field name to indicate this field is no longer used, and click save.
- Add your new field with the correct Field Type. Note the SQL field name cannot be the same as the old field.