comparing numerical values in a script

Hi all,

I've hit a wall with a script I'm working on and I'm hoping that someone out there has a suggestion for me. 

The purpose of the script is to compare the amount of a line in a bill and compare it to a custom currency field on the body of the vendor bill.  If the line amount is less than the body field, execute one set of actions, it the line amount is more than the body field, execute another set of actions.  Here is what I've got:

var amount = nlapiGetCurrentLineItemValue('expense', 'amount');
var currency = nlapiGetFieldValue('custbody_vba_level1approval');