inserting data to an existing node in xml

[bim11]

I'm new to both XML and PHP but I have this project and this is what needs to be done.I have an html form like this:\[code\]<table> <tr> <td align="right" width="120px">First name:</td> <td><input id="txtfname" style="width: 200px" type="text" /></td> </tr> <tr> <td align="right">Last name:</td> <td><input id="txtlname" style="width: 200px" type="text" /></td> </tr> <tr> <td align="right">Business name:</td> <td><input id="txtbisname" style="width: 200px" type="text" /></td> </tr></table>\[/code\]and I have an xml file like this:\[code\]<data> <first_name></first_name> <last_name></last_name> <business_name></business_name></data>\[/code\]is it possible to use a php file to write the data from the html forms to the xml file?If so, can anyone please tell me how. I really need to solve this problem.After this i also need to transfer the xml file to a sql database.I'm all ears.Thanks..