how to display ext_attributes

["michael arlt sk-schwanstetten de" <michael arlt sk-schwanstetten de>]

Hello!

Thanks for Dia and the ext_attribute feature.

I want to create administrative shapes e.g. a server has got a name (string), an operation system(string) and 
is of type cluster(bool). This is no problem with ext_attribute. But i want these attributes to get displayed 
in svg. A box with the text "OS: " and after this fixed text should appear the content of the ext_attribute 
"name".

Would be nice if you can give an example how to refer to the value?!

Thanks for any help!
Michael