//A set of tabbed pages is like a book. Here, each page has a tab and a block. Each tab has a radio button. 
function Book(){
	this.ids = new Array();
	this.addPage = function(id){
		this.ids.push(id);
		return true;
	}
}

function showTab(book, id){
	//for each page, show or hide:
	for(var i=0; i < book.ids.length; i++){
		if(book.ids[i]==id){
			//turn on:
			elById("blk_" + book.ids[i]).style.display = '';
			elById("tab_" + book.ids[i]).style.backgroundColor = '#f3f6f9'; 
			elById("tab_" + book.ids[i]).style.color = '#000000';
			elById("rdo_" + book.ids[i]).checked = true;
		}
		else{
			//turn off:
			elById("blk_" + book.ids[i]).style.display = 'none';
			elById("tab_" + book.ids[i]).style.backgroundColor = ''; 
			elById("tab_" + book.ids[i]).style.color = '#444444';
			elById("rdo_" + book.ids[i]).checked = false;
		}
	}
}

function elById(id, oDoc)
{
	if (!oDoc) oDoc = document;
	if (!oDoc || !oDoc.getElementById) return null;
	// case 311907: IE matches name as well as id,
	//              we only want id matches
	//
	try
	{
		var el = oDoc.getElementById(id);
		if (el && el.id != id) el = null;
		return el;
	}
	catch(e) {return null;};
}