rotX shootout

I am a self-taught programmer and here are my codes for generalized rot13:
perl:
sub rot{($_,$n)=@_;$a=join("","a".."z");$t=substr($a,$n).substr($a,0,$n-1);$T=uc($t);eval("tr/a-zA-Z/$t$T/");$_}
python:

def rot(x, n):
    r = lambda c, ord_a: chr(ord_a + (ord(c) - ord_a + n)%26)
    return ''.join(map(lambda c:(c>='a' and c<='z') and r(c, 97) or (c>='A' and c<='Z') and r(c, 65) or c, x))
javascript:

function rot(x, n){
        var r = function(c, ord_a){ return String.fromCharCode(ord_a + (c.charCodeAt(0) - ord_a + n)%26) };
        var r2 = function(c){ return (c>="a" && c<="z") ? r(c, 97) : (c>="A" && c<="Z") ? r(c, 65) : c };
        return x.split("").map(r2).join("")
}
Your comments are welcome. Feel free to guess my sex, age and sexual orientation :-)

$ python
Python 2.7.1+ (r271:86832, Apr 11 2011, 18:05:24)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 'hello, world'.encode('rot13')
'uryyb, jbeyq'