Exits for Actual Date in PS Module

Question

Hi Experts,
         I am having problem with Actual,Fixed and Schedule Dates in PS Module for Transaction CJ20N when we Selected the Milestone for an Activity, these above fields will appear.
When i Entering the Actual Date Keeping the Fixed Date Space, the date what i Entered in Actual Date is Updating in Schedule Date. Means both Actual and Schedule Date are Same.
      My Problem is ,  I can Change the Actual Date upto i Reached the System Date, and if the Actual Date is Greater than or Equal to System Date, Schedule Dates wont Change,if we wish to change the Actual Date, the schedule remains unchanged. But in my case this wont happen, if i give the Actual Date as a Future Date or Past Date, this date is updating in Schedule Date.
    Can anybody suggest the solution to solve this issue. If any User Exits or BADIs are there for those Fields, please help to solve this issue.

Answer 1

Hi,
       As u suggested, i had checked, but its not giving our desired result.
My Question is :
1. Fixed Date : If we give Fixed Date, It should take as Schedule Date, Once Scheduling Date (i.e. Fixed Date)    Equal to  System Date, Fixed Date should not Allowed to Edit. If Fixed Date is Less than System Date, then it should Allow to Change the Date.
2 .Actual Date : It should be Independent.It  should not influence other Fields.
3. Schedule Date : As Given Above, Fixed Date is nothing but Schedule Date..