How to get Reference Defect details to the current Defect

Hi All,

I needs to copy the Old / Reference defect fields values to current defect ID fields when there is a condion true.

I have a field called "Reference Defect ID (BG_USER_01)" where we can give old defect ID for reference,

now my condition is when this field is changed then the refered defect details should be copied to current defect fields i.e. BG_PROJECT, BG_DETECTION_VERSION, etc.

For Ex:

If BG_USER_01 = 5 THEN

BG_PROJECT = (Bug_fields.Field("BG_PROJECT").Value ''The value should be 5th defect value)

BG_DETECTION_VERSION = (Bug_fields.Field("BG_DETECTION_VERSION").Value 'THE VALUE SHOULD BE COPIED FROM 5TH DFECT field)

END if

Thanks In Advance,

Subbarao