Thanks for replying, are you referring the content under this link?
in detail, i reproduce the scenario as,
1. i create a document. (docx)
2. insert a text box (note not content control)
3. create custom property as you mentioned. (freegift...)
4. now i want to bind the customer property to textbox.
5. So that when i retrieve value from custom property i should get the value from text box what ever the user keyed in.
6. Am thinking in right direction, because the sample which you have shown is explaining how to bind values programmatically. (mine the other way round).
thanks for your help in advance,