error: TypeError: Cannot call method 'replace' of undefined

I'm trying to replace a substring by another one using this code:

var body = 'Message: ' + req.query.message.replace('/(?:\r\n|\r|\n)/g', '<br/>');

But, proceeding that way I get this error message on that line:

TypeError: Cannot call method 'replace' of undefined

I wasn't able to find the solution to fix this using javascript. What I've found is related to only jQuery.

Any brilliant idea how to fix that, please?