About tree control

Hi Friends,

Refer Transaction CJ20N.I am doing an enhancement in Transaction CJ20N.I have added a tab with few fields in the Project definition level as well as in the WBS Element level.The fields in WBS Element has got some dependancy over the fields in the Project Definition Level. Whenever i populate a particular field in the Project Definition level the value for all the subsequent WBS Element levels field has to be calculated and populated automatically.How to do this?.

Please lemme know if i am not clear. Prompt replies would be rewarded suitably. Its very urgent.

Thanks in advance.

Regards,

Tamilarasan.