function GE(id) {
	return document.getElementById(id);
};

function cambiarPuenteA(id) {
	GE('p0').className='';
	GE('p16').className='';

	for (var i=1; i<=15; i++) {
		GE('pTop'+i).style.borderColor='#000000';
		GE('pBottom'+i).style.borderColor='#000000';
		GE('p'+i).style.backgroundColor='';
		GE('p'+i).className='';
	};
	GE('p'+(id-1)).className='bordeDer';
	GE('p'+id).style.backgroundColor='#FFFFFF';
	GE('pTop'+id).style.borderColor='#FFFFFF';
	GE('pBottom'+id).style.borderColor='#FFFFFF';
	GE('p'+(id+1)).className='bordeIzq';

};


function makeObject(){
var x; 
var browser = navigator.appName; 
if(browser == "Microsoft Internet Explorer"){
	x = new ActiveXObject("Microsoft.XMLHTTP");
}else{
	x = new XMLHttpRequest();
}
return x;
}

var request = makeObject();
var divDestino = '';

function cargarPagina(pagina, destino){
var ran_number = Math.random()*4; 
divDestino = destino;
request.open('get', pagina + '?rand=' + ran_number);
request.onreadystatechange = parseInfo;
request.send('');
}

function parseInfo(){
if(request.readyState == 1){
	GE(divDestino).innerHTML = '<span class="cargando">Cargando P&aacute;gina...</span>';
};
if(request.readyState == 4){ 
	var answer = request.responseText;
	GE(divDestino).innerHTML = answer;
};
}

function mostrar(id,pagina) {
	cambiarPuenteA(id);
	cargarPagina(pagina, 'contenido');
	
}