Datepicker OnLoad PHP - Help ASAP please.

Datepicker OnLoad PHP - Help ASAP please.

First off sorry for demanding fast help. I just need this last part of the project to complete it hopefully today.
 
Ok I have datepicker on my site with two extra text fields. One id date to show the date the user selects the other two are 1) startdate and 2) enddate these two get the start fo the week and the end of the week for the week that date falls in that the user selects. This works great when a user actually selects a date, however is there anyway for these other two fields to load upon the page being loaded? I have the date field being auto populated by php from the database in the correct format d/m/Y so example 07/13/2010 but even though the date field shows this value from the database I cant get the startdate and enddate to populate onload unless the user selects the date again. Is there anyway to load these two upon page load?
 
ANY HELP GREATLY APPRECIATED....