@media screen {

	body.cls__main {
		background: url(/get_bg.php) center top repeat-x;
	}
}
<script type="text/javascript">
<!--
	f_get_tpl_path = function(arg_path) {

		var elemA = document.createElement('a');
		elemA.href = arg_path;

		console.log('f_get_tpl_path : ', '/tpl/basic01' + elemA.pathname);
		return '/tpl/basic01' + elemA.pathname;
	}
//-->
</script>