You can migrate the project  but the changes are very huge although you would not get any error or many difficulity around this changes in version but you will not gain many advantages regarding the migrate.
because one of the main power of 11g is its ADF Faces in UI that when you migrate you can not user the new one too and also the UI is not migrate from the 10g  trinidad to 11g rich faces.
I would be appreciated if you informed me where and the scope of the location/project that you are handling in Jdeveloper.
I hope to be helpful.
And also do you have any ADF 11g programmers wanna be hired?

my project  is a web application that uses ADF and jsp,i can't undrestand this sentence"the changes are very huge although i would not get any error or many difficulity around this changes in new version"??? i think it is contradiction.

one of the reason of this migration is ui and ADF faces.

i have another questions,1.how can i show the date of today automatically(editable),in timesheetview1_edit.jsp form when form be shown.(now i use UI control hints)

and 2. how can i show the username of person that log in to sytem in name field of timesheetview1_edit.jsp form (uneditable)?

3.how can i change the date field to two fields:startdate and end date in timesheetview1_query.jsp form however in table i have just date column?

i use dataeditcomponent.jsp,datahandllercomponent.jsp,datatablecomponent.jsp and...

unfortunately,i don't have any ADF programmer with free times.

sorry for the paradoxical sentences!( based of your conjecture)

what I want to explain by that sentences is that:
when you do migration, there would be many change in your project  in the base files ( main file). and the migration process is not hard.
And migrating from 10g  to 11g would not give you many advantages if your reason is the UI components. because the UI would not change after the migration.
you did not tell me about the project/compnay scope of the application ...

thanks for your explanations.

it is a project  control software that will be used in a research institute.

if you need more details to answer those question ,i'll tell you.