function centrarCapa(obj){	
	//var a = parseInt($(obj).css("width"));	
	//var h=(document.body.clientWidth-a)/2;
	//$(obj).css("left",h);

	var a = parseInt($(obj).css("width"));	
	//var h=(document.body.clientWidth-a)/2;
	var myWidth = 0;
	if( typeof( window.innerWidth ) == 'number' ) {
		//Non-IE
		myWidth = (window.innerWidth-a)/2;
	} else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
		//IE 6+ in 'standards compliant mode'
		myWidth = (document.documentElement.clientWidth-a)/2;
	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
		//IE 4 compatible
		myWidth = (document.body.clientWidth-a)/2;
	}
	$(obj).css("left",myWidth);

};


function mostrarCapa(capa){
	$(capa).slideDown("slow");	
}

function ocultarCapa(capa){
	$(capa).hide("slow");
}