if (document.all && /MSIE (5\.5|6)/.test(navigator.userAgent) &&
  document.styleSheets && document.styleSheets[0] && document.styleSheets[0].addRule)
 {
  document.styleSheets[0].addRule('*', 'behavior: url(js/iepngfix.htc)');

 }

<!--
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];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0

  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->

function demoRequestJson(){

	if(document.getElementById("nombre").value == ""){
		document.getElementById("nombre").style.border = "1px solid #C00";
		setTimeout('fueraborde("nombre")',2000)
		
		}
	if(document.getElementById("email").value.indexOf("@") == -1 || document.getElementById("email").value.indexOf(".") == -1){
		document.getElementById("email").style.border = "1px solid #C00";
		setTimeout('fueraborde("email")',2000)
		
		}
	if(document.getElementById("comentarios").value == ""){
		document.getElementById("comentarios").style.border = "1px solid #C00";
		setTimeout('fueraborde("comentarios")',2000)
		
		}
	
	else{
	
       var jsonRequest = new Request.JSON({  
           url:    'mail.php',  
           method: 'post',  
           data:   $('mandamail'),  
     
           onRequest: function()  
           {  
        document.getElementById("loading").style.display = "block";
		document.getElementById("campos").style.display = "none";  
           },  
     

     
           onSuccess: function(responseJSON, responseText)  
           {  
        document.getElementById("loading").style.display = "none"; 
		document.getElementById("completado").style.display = "block";
           },  
     
           onFailure: function(xhr)  
           {  
		document.getElementById("loading").style.display = "none";
        document.getElementById("error").style.display = "block";
           }  
       }).send(); };
};



function limpiar(donde){
	
	document.getElementById("campos").style.display = "block"; 
	document.getElementById(donde).style.display = "none";
	document.getElementById("nombre").value = ""; 
	document.getElementById("email").value = "";
	document.getElementById("comentarios").value = "";
	};
	
	
function fueraborde(donde){

	document.getElementById(donde).style.border = "0px";
	
	}