Check Boxes and Cacluated Fields

I am trying to create a trave & traing PDF form.  I’m running into issues with the following…

If the check box is checked the employee gets reimbursed.  If it s not checked the company paid for the expense. They will type the amount in the amount fields.

I would like a summary that totals each section (see below) but I’m finding some issues and I’m not sure how to ask the question and get any response that makes sense.  I also do not right JavaScript.

If I add the a sum using the calulate tab in text field properties using the amount total  of each section, it cannot be overwritten or corrected.

I’ve tried an “if” formula found on the web to add add the amount if checked.  It didn’t function as I had hoped.

Ideally I would like it to add the amount recorded in the transportation field if checked – under the Employee Reimbursement and if unchecked it goes into the Event Expenses.

Employee Check Request Total totals everything under Employee Reimbursement.  Total Event Expense Totals the calculated amounts under Event Expenses plus the amount Employee Check Request Total. I do not mind if it adds from the category totals. 

Side note: The transportation totals could be a combination of the categories.