Set Class in Estimate

This seems like it should be so simple, so I must be missing some small piece here. I'm trying to set the Class field automatically when a new Estimate is created base off of the current user (Class is a single body field not in the item column). I grab the current user id, which works (tested with an alert), but it won't load the employee record - it fails on line 2. I even hard coated in a known employee id number and it still didn't work. We're on v2007. What am I doing wrong here?

function SetClass()
{
var empid = nlapiGetUser();