function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}



	var category='';
	
	function GetXmlHttpObject(handler)
	{ 
	var objXmlHttp=null
	if (navigator.userAgent.indexOf("Opera")>=0)
	{
	  alert("This example doesn't work in Opera") 
	return 
	}
	if (navigator.userAgent.indexOf("MSIE")>=0)
	{ 
	var strName="Msxml2.XMLHTTP"
	if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
	{
	strName="Microsoft.XMLHTTP"
	} 
	try
	{ 
	objXmlHttp=new ActiveXObject(strName)
	objXmlHttp.onreadystatechange=handler 
	return objXmlHttp
	} 
	catch(e)
	{ 
	alert("Error. Scripting for ActiveX might be disabled") 
	return 
	} 
	} 
	if (navigator.userAgent.indexOf("Mozilla")>=0)
	{
	objXmlHttp=new XMLHttpRequest()
	objXmlHttp.onload=handler
	objXmlHttp.onerror=handler 
	return objXmlHttp
	}
	}
	


function show_frame(page)
	{ 
		var url= page;
		document.getElementById("main_data").innerHTML="<div align='center'> <img src='../images/loader.gif' border=0 vspace='50'></div>"; 
		xmlHttp=GetXmlHttpObject(stateChanged);
	    xmlHttp.open("POST", url , true);
	    xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
		xmlHttp.send("");
		
		 //var t=setTimeout("mostrar_book()",250);
	} 
	function stateChanged() 
	{ 
	  if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	  {
	    document.getElementById("main_data").innerHTML=xmlHttp.responseText;
	  } 
	}