HTML and CSS Reference
EXPLANATION ( CONTINUED )
The select menu starts here with three options, each a credit card type.
This is the text box where the user enters the card number.
When the user clicks the submit button, the onSubmit handler is invoked, and if
the credit card number passes the validity test, off goes the form! See Figure 17.52.
Figure 17.51 Some valid credit cards, their prefix, length, and whether they pass the
Lunh test based on modulus 10, shown later. Source:
Figure 17.52 The number of characters in the credit card number should be 16 for