Jquery pre loader on wp

// preloader image

function wpb_preloader_image (){
	$wpb_preloader_gif_src = plugins_url( 'assets/images/preloader_3.gif' , __FILE__ );
	?>
		<div class="wpb_preloader">
			<img src='<?php echo $wpb_preloader_gif_src; ?>' alt="" />
		</div>
	<?php
}
add_action('wp_footer','wpb_preloader_image');

// preloader script

function wpb_flat_preloader_trigger(){
?>
	<script>
		jQuery( window ).load(function() {
			jQuery(".wpb_preloader").fadeOut('slow');
		});
	</script>
<?php
}
add_action('wp_footer','wpb_flat_preloader_trigger',999);

// preloader style
function wpb_preloader_style (){
?>
	<style>

	.wpb_preloader {
		background: none repeat scroll 0 0 #FFFFFF;
		height: 100%;
		left: 0;
		position: absolute;
		text-align: center;
		top: 0;
		width: 100%;
		z-index: 9999;
	}
	.wpb_preloader > img {
		margin-top: 20%;
	}

	</style>
<?php
}
add_action('wp_head','wpb_preloader_style');