Having trouble with email rule

Having trouble with email rule

I have a checkbox set up, I will give an example of 3 options for a field called "Drivers"

Jim

Sue

Thad

I want each selection to email a notification to the specific person included. This works if you only select 1. Unfortunately if I select more than one it seems to break my rule and doesn't detect it.

For instance....If I set up a task for emailing Thad when it is selected and the form is sent, if Thad is only selected it will work but if I have Sue and Thad selected it wont. I'm sure I'm just not using the currect syntax in making sure it contains the right name.

Current syntax I have it set to is Drivers Contains "Thad"or  condition    : (Drivers_Field.contains("Thad"))