To focus on a login input box with id 'login' on page startup : focus « jQuery « JavaScript Tutorial

$(document).ready(function(){
  $("#login").focus();
});

30.43.focus
	30.43.1.	Set focus to text box
	30.43.2.	Fire focus event
	30.43.3.	Set focus form field
	30.43.4.	Trigger focus event
	30.43.5.	To focus on a login input box with id 'login' on page startup