// Documento JavaScript Mostrar-Ocultar Capas
var version = parseInt(navigator.appVersion);

function init(){
	if(document.layers || (navigator.appName == "Netscape" && version != 5)){
		//alert("layers");
		//alert(winH);alert(winW);
		var altura = ((winH-450)/2) - 50;
		if (altura < 0){ altura= 0;}
		document.layers['principal'].top = altura;
		document.layers['principal'].left = (winW-594)/2;
	}else if(document.getElementById){
		//alert("get");
		var altura = ((winH-450)/2) - 50;
		if (altura < 0){ altura= 0;}
		document.getElementById('principal').style.top= altura;
		document.getElementById('principal').style.left= (winW-594)/2;
	}else if(document.all){
		//alert("all");
		var altura = ((winH-450)/2) - 50;
		if (altura < 0){ altura= 0;}
		document.all['principal'].style.top = altura;
		document.all['principal'].style.left = (winW-594)/2;
	}
}

function mostrarcapa(nombrecapa){
//alert(nombrecapa);
	if(document.layers || (navigator.appName == "Netscape" && version != 5)){
		
		document.layers.principal.document.layers[nombrecapa].visibility = "show";
	}else if(document.getElementById){
		document.getElementById(nombrecapa).style.visibility = "visible";
	}else if(document.all){
		document.all[nombrecapa].style.visibility = "visible";
	}
}

function ocultarcapa(nombrecapa){
	if(document.layers || (navigator.appName == "Netscape" && version != 5)){
		document.layers.principal.document.layers[nombrecapa].visibility = "hide";
	}else if(document.getElementById){
		document.getElementById(nombrecapa).style.visibility = "hidden";
	}else if(document.all){
		document.all[nombrecapa].style.visibility = "hidden";
	}
}