immediate function example

gistfile1.js

var days = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
today = new Date(),
msg = 'Today is ' + days[today.getDay()] + ', ' + today.getDate();
alert(msg);


//////////////////////////////////////////////////////////////////


(function () {
  var days = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
  today = new Date(),
  msg = 'Today is ' + days[today.getDay()] + ', ' + today.getDate();
  alert(msg);
}());