function preloader() {
	
	for(i=0; i<preloaded_images.length; i++) {

		var loaded_image=new Image();
		loaded_image.src=preloaded_images[i];
	}

}

function roll_related(area_num,img1_over,img2_over) {

	$('related_area' + area_num).style.background = '#FFFFFF';	

	// get image names from parent div	
	
	if($('1related_image' + area_num)) {
	$('1related_image' + area_num).src = img1_over;
	}

	if($('2related_image' + area_num)) {
	$('2related_image' + area_num).src = img2_over;
	}
	
}

function unroll_related(area_num,img1_off,img2_off) {

	$('related_area' + area_num).style.background = '#E5E5E5';	

	
	if($('1related_image' + area_num)) {
	$('1related_image' + area_num).src = img1_off;
	}

	if($('2related_image' + area_num)) {
	$('2related_image' + area_num).src = img2_off;
	}	
	
}