File I/O

[Kirt]

Hi! I need some help in file I/O

I have an xml file..

<Top>
<Body1>xyz</Body1>
</Top>

I want to open these file in append mode and add the line
<Body2>abd</Body2>

Such that i have:

<Top>
<Body1>xyz</Body1>
<Body2>xyz</Body2>
</Top>

can anyone show me the way to achieve this?? 

thanx