A valid e-mail address
var validEmail = "a@t.com";
var invalidEmail = "d@t";
var pattern = /^[\w\.\-]+@([\w\-]+\.)+[a-zA-Z]+$/;
var a = pattern.test(validEmail);
var b = pattern.test(invalidEmail);
document.write(validEmail + " is valid: " + a + ", " +invalidEmail + " is valid: " + b);