The 'Find Trk' button FINDS all load(s) for the truck (Trk), or unit #, and sort the found loads by unit (rather than the default pro order). 

1) Click on the 'Find Trk' button, enter the unit # you wish to search for, and click the ok button (or press enter).

2) Navigate between the loads using the VCR style back/forward controls.

3) Be sure you press the 'CANCEL SEARCH' button to return the sort order to normal(by pro)