Problem with parsing I need to insert...

Hey guys if u or any of ur friends who knows the following parses plz tell me a solution for solving the the following problem. This is not updating its inserting... k,,

dom parsers....
jdom parser
sax parser

Need ur help...

I have an XML file.....
The procedures are like this...
A User will get registerd with the site...and fill in the details ....
AT the end the enterd detaisl will get stored into the XML file...
And on every visit the user do.....the user will attend the test online and at the end of the test....The marks will be included ...

SO now the XML file will ook like this....

1.During registraion

<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
</UserId>

2.At the end of the Ist Test
<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
<test1>57</test1>
</UserId>

3.At the end of the IInd Test
<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
<test1>57</test1>
<test2>78</test2>
</UserId>

4.At the end of the IIIrd Test
<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
<test1>57</test1>
<test2>78</test2>
<test3>23</test3>
</UserId>

Now if u see the tags very closely...
The <test> tag gets inserted....on every end of the exam......
So how can this be achived

pls help me out....

You can even tell me the solution for the following issue.. I wanted the output this.. way

At the end of the Ist Test

<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
<test>
java_57
</test>
</UserId>

At the end of the IInd Test

<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
<test>
java_57,c++_87
</test>
</UserId>

At the end of the IIIrd Test

<UserId>987979
<name>GHanesh</name>
<age>24</age>
<sex>M</sex>
<qualification>B.E</qualification>
<test>
java_57,c++_87,c_90
</test>
</UserId>