Dear R-Gurus! I have read an xml document with xmlTreeParse and can access that attribute value by xmlGetAttr or xmlAttrs What I want to do is to set a new value and to write the modified DOM tree into an XML file. But until now I have not found an setter method equivalent to the getter method? Eryk -- Witold Eryk Wolski __("< School of Mathematics and Statistics _ \__/ University of Newcastle 'v' || Newcastle upon Tyne, NE1 7RU, ENGLAND / \ ^^ mail: witek96 at users.sourceforge.net m m Phone : 044 (0)191 222 5376 FAX : 044 (0)191 222 8020