Turn off and on Overwrite Mode in interwoven

System

Hi,

I am using interwoven Teamsite 6.5.Whenever i am generating my xml files form datacapture.cfg, i am not able to save the xml in the same file name which is already existing.The system again opens a popup window and ask me to save.How to switch on or off overwrite mode in interwoven.
Kindly advise,

Thanks in advance