Hello again!!Now, my question is when the ATC clears you to start the descent before the T/D point... For example, "the aircraft is cruising F370 and the ATC clears you to descend and maintain initially F250"...Which procedures do I have to follow, and What happen with the Vertical deviation displayed on the NAV Display, How to reestart our descent with the FMC parametes when the ATC crears you to continue you descent as filed...Thank you in advanced!Santiago:)

I go into the VNAV page and select the DES NOW > LSK. I do not know if that is proper procedure but it'll start a nice slow descent for the airplane.

set the assigned altitude in the MCP and use the decend now feature of the FMC. If you just hit "Decend now" the FMC will take you below your assigned altitude to your next altitude restiction. If you recieve clearance to continue decent before leveling out just set the altitude of your clearance or altitude restriction in the MCP. If you leveled off at your interim altitude assigned then set the altitude in the MCP. if the aircraft does not start decending hit Decend now in the FMC to start your decent.Ray