Sample of loading assets in WordPress

wp-enqueue-assets.php

<?php
 /*
  * @pakage WordPress
  * This file resolve external js and css loading and their chaching.
  * Put this file in your theme foloer and 
  * write the line below in your theme's "functions.php"
  *
  * require_once(TEMPLATEPATH."/wp-assets.php");
  *
  */

// define version
define("MY_THEME_VERSION", "1.0");

/**
 * Hook on "init" action.
 */
function my_thmeme_init(){
	//If this loaded page is not admin panel
	if(!is_admin()){
		add_action("wp_enqueue_scripts", "my_enqueue_script");
		add_action("wp_enqueue_styles", "my_enqueue_style");
	}
}
add_action("init", "my_theme_init");

/**
 * Load CSS. Add "wp_enqueuew_style" function as you like.
 */
function my_enqueue_style(){
	/*
         * About wp_enqueue_style, see below
         * http://codex.wordpress.org/Function_Reference/wp_enqueue_style
         */
	wp_enqueue_style(
		"my-theme",
		get_bloginfo("stylesheet_url"),
		array(),
		MY_THEME_VERSION
		"screen"
	);
        //This "if" block is valid only in Internet Explorer.
	global $is_winIE; 
	if($is_winIE){
		wp_enqueue_style(){
			"ie6",
			get_bloginfo("template_directory")."/js/ie6.css"
		}
	}
}

/**
 * Load JS
 */
function my_enqueue_script(){
	/*
         * About wp_enqueue_script, see below
         * http://codex.wordpress.org/Function_Reference/wp_enqueue_script
         */
	wp_enqueue_script(
		"my-script",
		get_bloginfo("template_directory")."/js/my.js",
		array("jquery"),  
		MY_THEME_VERSION,
		true              //If true, <script>tag will be written in wp_footer
	);
	if(is_singular()){ //You can use any conditional tags.
		wp_enqueue_script(
			"my-single",
			get_bloginfo("template_directory")."/js/single.js",
			array("prototype"),
			MY_THEME_VERSION,
			true
		);
	}
}