edeting .xml files

Hi... Me and my School mates are having an experiment where we have to note down the data for each time... (the assigment is; exersice and note down, pulse, temprature, and so on....)

And so i thought i can use C#.net and xml for this, and then display the data using xsl....

But how can i ADD tags with data to an existing .xml file?

so say i have this xml file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<data>
<input>
<date>X</date>
<pulse>X</pulse>
<temp>X</temp>
<timer>X</time>
</input>
</data>

the by a form (text boxes and labels and stuf) enter data and make it like this... (still the same file)

<?xml version="1.0" encoding="ISO-8859-1"?>
<data>
<input>
<date>X</date>
<pulse>X</pulse>
<temp>X</temp>
<timer>X</time>
</input>
<input>
<date>Ydate>
<pulse>Y</pulse>
<temp>Y</temp>
<timer>Y</time>
</input>
</data>
and then keep on going, adding more data and so on...
And PLEASE make it reall simple, no fancy error exceptions....

just real simple.... INPUT DATA, OPEN XML FILE, WRITE NEW DATA TO FILE, CLOSE FILE & PROGRAM :D

thanks in advance if some one helps me on this...

[1434 byte] By [Andreas-Moe] at [2008-2-4]
# 1
With the new systems you can bind your data controls to an xml file, this will act the same ways as if you were connecting to a database.
GlennWilson at 2007-9-8 > top of Msdn Tech,Visual Studio Express Editions,Visual C# 2005 Express Edition...