SASS: Psuedo test

psuedo element background image.scss

&:before{
	content:"";
	display: block;
	position: absolute;
	$image_uri: "sprites/tab/bg1.png";
	@include background(url('#{$themeURL}/images/#{$image_uri}') repeat-x top left);
	width: image-width($image_uri);
	height: image-height($image_uri);
	top: 0;
	left: -(image-width($image_uri));
}