XML : Is there some function to get a XML from an string as JavaScript object?

I want any function to return an XML from a string as JavaScript Object (not JSON), which throw tags and their attributes.

Yeah, there are already questions about this that are not what I'm looking. I found this thing that is what I want, but it makes the XML tags name in JavaScript Object property be lowercase.

I have been working in a function just breaking out and solved to find some function in some websites.

I'd like to get a suggestion of what function to use that doesn't change uppercase to lowercase, etc.