XML content editor... but not the tags!

Does anyone know of a program that can edit XML files but not screw up the actual tags… so for example:


<myxml>
     <myContent file="testing.swf" link = "here.htm"/>
</myxml>

And it would only let the user edit “testing.swf” or “here.htm” and not let them screw up the actual code and tagging behind the file?