Oracle Forms

hii all
i have two fields from_time to to_time
they are of lke
from to
1700 1900
1900 2100
i have to make sure that the to time of the previous record is equal to the start time of the next recod
if the user updates any to_time
then the rest should be automatically updates accordingly
from_time is display only field
when a new record is created the from_time is autoppulated with the end time of the previous record


can any one give me any ideas about how to do it ?
pllzz help me
Mandar
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hii i have developed the logic for above
but there are some problems i am facing
I have written an update statement in the when validate item of to_time to update the start time ..
when i change the end time and then click save everything works fine
but when i change the end_time and directly close the form and again open it the changes are not reflected
again when i save it the changes re reflected
how can i overcome this
for eg
1)initialy
from to
1700 1800
1800 1900
1900 2000

2) i change the value
from to
1700 1800
1800 1930--changed
1900 2000

3) i click save button

from to
1700 1800
1800 1930
1930 2000

it workds fine

4)after changing the record i do not click save buton and exit the form
then the following is shown
from to
1700 1800
1800 1930
1900 2000
which is not allowed ..
now i again click save and the changes re reflected

from to
1700 1800
1800 1930
1930 2000

i want that when i close the button the records must be saved and then exit the form
and when i again open theform the changes must be visible
plzzzz help me
thanks
manadr

Message was edited by:
bindok mulga