How to avoid & in XML ?

[chrslp]

I am trying to send all data to xml through php. But somehow XML parses the data and in Password it finds \[code\]&\[/code\] and replaces it with \[code\]&\[/code\] after that data is posted through Curl. So is there any method / technique to avoid \[code\]&\[/code\] in xml. Or it goes as it is. I am tried almost all encoding functions.