It saves you bandwidth, server load and it saves time for your users.
In the example above, we load both French and Italian translations, and use Italian.
Here the Username and Password entered by the user is passed to the stored procedure and its status is captured and if the value is not -1 (Username or password incorrect) or -2 (Account not activated) then the user is redirected to the Home page using Hi, This is Mudassar Khan. Net Question Answer site, specially started to allow visitors of this site ask their doubts and queries. Just click the Ask Now button and ask your question now.
For almost all credit cards, the Luhn Formula is used.
This algorithm generates a single digit which is then used as the last digit of the card number. It merely triggers a call to the Java Script function to check the number (you can view the page source to see this for yourself).
They follow whatever coding scheme that particular card company chooses.