function section_highlight(menuid){
	var menuitem = document.getElementById(menuid);
	menuitem.style.backgroundColor = "yellow";
	menuitem.style.borderColor = "black";
}

function section_unhighlight(menuid){
	var menuitem = document.getElementById(menuid);
	menuitem.style.backgroundColor = "#66CC66";
	menuitem.style.borderColor = "#66CC66";

}

function cs_content_highlight(menuid){
	var menuitem = document.getElementById(menuid);
	menuitem.style.backgroundColor = "#336633";

}

function cs_content_unhighlight(menuid){
	var menuitem = document.getElementById(menuid);
	menuitem.style.backgroundColor = "#003333";
}

function cs_change_content(contentid, contentimg){
	var content_item = document.getElementById(contentid);

	var productimage = document.getElementById("productimage");
	productimage.src = contentimg;
	
	//hide all
	for (i=1;i<8;i++)
	{	
		content_element = "content_" + i;
		var contentitem = document.getElementById(content_element);
		contentitem.style.visibility = "hidden";
	}

	// show content
	content_item.style.visibility = "visible";
}