what is the difference between eatch coins wallet address,what is the coin public id/salt? i looked at the link: http://brainwallet.org/

witch generate offline wallets for all major coins,
i noticed that the same Passphrase generate different  [Private Key&amp;Address] pairs for eatch coin type, witch means eatch coin has a public shared id (or salt) added to the mix of the hash, am i right?

so how can i get that public coins key? and how can i edit the javascript  to support other scrypt coins? 

eatch time i change coin in the menu a function is called,
i got that code of the page:

  PUBLIC_KEY_VERSION = parseInt($(this).attr('data-target'));
  PRIVATE_KEY_VERSION = (PUBLIC_KEY_VERSION+128)&amp;255;
  ADDRESS_URL_PREFIX = $(this).attr('href');
 ....
    var eckey = gen_eckey;
    var compressed = gen_compressed;
    var hash_str = pad($('#hash').val(), 64, '0');   
    var hash = Crypto.util.hexToBytes(hash_str);

    var hash160 = eckey.getPubKeyHash();        
    var h160 = Crypto.util.bytesToHex(hash160);
    $('#h160').val(h160);

    var addr = new Bitcoin.Address(hash160);
    addr.version = PUBLIC_KEY_VERSION;

    $('#addr').val(addr);


when addr is the wallet address....

and the data-target  for the links are:

bitcoin : 0x00
dogecoin: 0x1E
litecoin: 0x30
namecoin: 0x34
.
.
.


is this is the uniqe identifire of the coin? is if possible? 
it's just a single byte...

if not than what is?, and if yes how can i get the identifier of other coins, not listed (any way to extract it from the network/wallet software)?

thanks
Yes, currencies like Bitcoin typically have a version byte that gets stored in the address which would be the PUBLIC_KEY_VERSION in the code you found.

More information here:

https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses

https://en.bitcoin.it/wiki/List_of_address_prefixes

There is another byte used for private keys as well. See:

https://en.bitcoin.it/wiki/Wallet_import_format

These bytes can't really uniquely identify a coin but they should make it harder for users to accidentally send Bitcoin to a Dogecoin address or make other mistakes like that.