Not able to set content type

[zentosd]

i have an xmlfile , as
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<SConfig>
<Address>192.168.0.189</Address>
<Key>18ADCC435791F0B29593733532FDFC71</Key>
<Number>0</Number>
</SConfig>

which has to be sent to as response and it wil be opened by .(dot) extension mapping. like .doc mapping. can i use any content type.. need full code

i am using ony html and javascript...no php or jsp....