Very Helpful!!!
"With regard to the portability rule, we strongly suggest aliens under this category wait for the approval of their I-140 before changing employer. If the aliens feel like they really need to do so before the approval of I-140, there are two suggestions. One is to strictly follow the 180-day rule, i.e., to change employer (if they really feel like to) 180 days after I-485 is filed. The other is always ask new employer to file new H-1 or L-1 for them before they leave current employer, so that they have valid H-1 or L-1 status during the I-485 pending period."
Thanks a lot for providing the link!!!