Backslashes - Regular Expression - Javascript

I wanted to create a JS function that combines an argument list into a valid path (since I couldn’t be sure if part of the path was given with or without a slash)

This is the function:

concatPath = function() {
    var path = "";
    for(var i = 0; i < arguments.length; i++)   {
        path += arguments[i].replace("(\\|/)$|^(\\|/)", "") + "/";
    }
    return path;
}

Used by RegEx matched all leading and trailing slashes and backslashes at http://regexpal.com But the function does not work correctly (RegEx does not match). Chrome also indicates

SyntaxError: Invalid regex: / () $ | ^ () /: Unterminated group

when I just use RegEx

 (\\)$|^(\\)

However, using RegEx

 (\\)$|^(\\)

works great.

Too late or did I miss something special?

Thanks in advance!

Leo