Regarding adding row in config file

Question

hi dear

i have following xml file....

<FPWebBox>

  <Configuration>
 
  
    <ConsumerAuthenticationDetails>
      <consumer wsusername="[email protected]" wspassword="user1" wsportalurl="www.portal1.com" />
      <consumer wsusername="[email protected]" wspassword="user2" wsportalurl="www.portal2.com" />
      <consumer wsusername="[email protected]" wspassword="user3" wsportalurl="www.portal3.com" />
    </ConsumerAuthenticationDetails>

    <ConsumerPrefrencesDetails>
      <consumerprefrences wsusername="[email protected]" loging="true" sessionquota="2000" />
      <consumerprefrences wsusername="[email protected]" loging="true" sessionquota="2000" />
      <consumerprefrences wsusername="[email protected]" loging="false" sessionquota="2000" />
    </ConsumerPrefrencesDetails>

  </Configuration>

</FPWebBox>

i want to add a row in both <ConsumerAuthenticationDetails> and  <ConsumerPrefrencesDetails> . i am doing that with the help of reading xml into dataset then creating a new row for each type (<ConsumerAuthenticationDetails>, <ConsumerPrefrencesDetails>) inserting values and adding back the rows to table but it is inserting the values just before the ending of root node (</FPWebBox>)

please help me in the matter...

regards

vishal