function banner_show(){
	//alert("entre");
	 //sets a layer with the banner
	 var IE4 = (document.all && !document.getElementById) ? true : false;
	   var NS4 = (document.layers) ? true : false;
	   var NS5 = (document.layers) ? true : false;
	   var IE5 = (document.all && document.getElementById) ? true : false;
	   var N6 = (document.getElementById && !document.all) ? true : false;

	   var ancho;
	   var alto = 300
	   if (NS4) {
	     ancho = parseInt((window.innerWidth - 273)/2);
	     document.writeln('<layer name="blockDiv" left=' + ancho + ' top=' + alto +' width=68 height=68 >');
	     document.writeln('<img src="images/loadData.gif">');
	     document.writeln('</layer>');
	   }
	   else {
	     ancho = parseInt((document.body.clientWidth -273)/2);
	     document.writeln('<div ID="blockDiv" style="position:absolute; left:' + ancho + 'px; top:' + alto + 'px; width:68 px; height:68 px;z-index: 5;' +  '">');
	     document.writeln('<img src="images/loadData.gif">');
	     document.writeln('</div>');
	}
}

function banner_hide(){
	//alert("done");

	var IE4 = (document.all && !document.getElementById) ? true : false;
	var NS4 = (document.layers) ? true : false;
	var IE5 = (document.all && document.getElementById) ? true : false;
	var N6 = (document.getElementById && !document.all) ? true : false;

    var NS5 = (document.layers) ? true : false;

	//hide banner
	if (NS4) document.layers['blockDiv'].visibility = "hide";
    if (N6) document.getElementById('blockDiv').style.visibility = "hidden";
    else document.all['blockDiv'].style.visibility = "hidden";
}