Regular Expressions in Javascript

Tham khảo tại:
http://www.w3schools.com/jsref/jsref_obj_regexp.asp
http://net.tutsplus.com/tutorials/other/8-regular-expressions-you-should-know/
ví dụ:
yyyy-mm-dd:

/^(\d{4})-(\d{1,2})-(\d{1,2})$/

file đuôi .wav :

/(\.wav)$/

áp dụng:

re = /^(\d{4})-(\d{1,2})-(\d{1,2})$/;
if (frm.date.value != '' && !frm.date.value.match(re)) {
alert("Invalid date format: " + frm.date.value);
form.date.focus();
return false;
}

Thks & rgds!