Loading javascript
jQuery('.loading').fadeOut();
<header class="clearfix">
<span class="loading"><img src="images/ajax-loader.gif" alt=""></span>
</header>
.loading
position absolute
background #2a2a2a
z-index 999
height 100%
width 100%
left 0
img
width auto
position absolute
top 0
left 0
right 0
bottom 0
margin auto