If you are using validation for the required field, you will want to add an "AND" rule.
Ex:
Condition
OverallStatus is equal to 1 AND
RichTextBox is blank OR
OverallStatus is equal to 2 AND
RichTextBox is blank
Screentip
Please fill out this field. (This can say whatever you want it to say)
Without the "is blank", the validation will always require that you fill out the field since you are only checking to see that OverallStatus equals 1 or 2.
The "is blank" makes the field required until you type something into the field.
Hope this helps.
G Moore