my jQuery not working

my jQuery not working

I'm a new bie , but have been following some video tutorials. i tried some jquery code to change the background color of my textboxes  when it receives focus, but nothing happens. i downloaded the latest version of jQuery, using the latest version of Firefox, Chrome, IE and also using windows 7 64bit OS. below is my code.
HTML FILE:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<script  src="js/jquery.js" type="text/javascript" />
<script  src="js/styler.js"  type="text/javascript"></script>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<link href="styles.css" rel="stylesheet" type="text/css" />
<!-- #BeginEditable "doctitle" -->
<!-- #EndEditable -->
MY Custom JQuery FILE:

$(':text').focusin(function ()

{
$(this).css('background-color','grey');
});

$(':text').blur(function(){
 
 $(this).css('background-color','transparent');
 
});