I would like for someone to give me the steps needed to get this module working correctly. I have the module installed already but when trying to check out get the error.

Code:
An error occured with the USPS shipping calculations.
If you prefer to use USPS as your shipping method, please contact the store owner.
Obviously it is a error with shipping calculations. Do I edit these calculations in the usps.php file and if I do edit them there what should they be edited to.

Thanks

DW