var font_color_normal = "#BBAE99";
	var font_color_hover = "#FFFFFF";
	var number_of_images = 6;
	
	function why(id, id_img, action) {
		if (action == 'on') {
			document.getElementById('why-content-' + id).style.backgroundImage = "url(" + img_bcg_hover.src + ")";
			document.getElementById('why-title-' + id).style.backgroundImage = "url(" + img_bcg_hover_title.src + ")";
			document.getElementById('why-content-' + id).style.color = font_color_hover;
			changeImage(id_img);
		} else {
			document.getElementById('why-content-' + id).style.backgroundImage = "url(" + img_bcg_normal.src + ")";
			document.getElementById('why-title-' + id).style.backgroundImage = "url(" + img_bcg_normal_title.src + ")";
			document.getElementById('why-content-' + id).style.color = font_color_normal;
		}
	}
	function changeImage(id_img) {
		for (i=1; i<=number_of_images; i++) {
			if (document.getElementById('img-header-' + i)) {
				document.getElementById('img-header-' + i).style.display = "none";
			}
		}
		if (document.getElementById('img-header-' + id_img)) {
			document.getElementById('img-header-' + id_img).style.display = "inline";
		}
	}