function nomdomvalido(nombre)
{

  var checkOK = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-";
  var checkStr = nombre.value;
  var allValid = true;

  if (checkStr.length > 67 ) allValid = false;
  if (checkStr.length < 1  ) allValid = false;
 
  ch = checkStr.charAt(1);
  if (ch == "-") allValid = false;

  ch = checkStr.charAt(checkStr.length);
  if (ch == "-") allValid = false;

  if (allValid)
  {
    for (i = 0;  i < checkStr.length;  i++)
    {
      ch = checkStr.charAt(i);
      for (j = 0;  j < checkOK.length;  j++)
        if (ch == checkOK.charAt(j))
          break;
      if (j == checkOK.length)
      {
        allValid = false;
        break;
      }
    }
  }

  if (!allValid)
  {
    return (false);
  }
  return (true);
}

function navegador() {
//-------------------------------------------------------------
//      Veamos que browser nos ha invocado...
//-------------------------------------------------------------
var is_mac = 0;
var is_unix = 0;
netscape = 0;
msie = 0;
proddescsize = "x-small";
browserName = navigator.appName.substring(0,8);
browserVer = parseFloat(navigator.appVersion);

if (navigator.appVersion.charAt(navigator.appVersion.indexOf("(")+1) == "M"){
        is_mac = 1;
        }
else if (navigator.appVersion.charAt(navigator.appVersion.indexOf("(")+1) == "X"){
        is_unix = 1;
        }
else if (navigator.appVersion.charAt(navigator.appVersion.indexOf("(")+1) == "L"){
        is_unix = 1;
        }
else if (navigator.appVersion.charAt(navigator.appVersion.indexOf("(")+1) == "O"){
        is_unix = 1;
        }
if (navigator.appVersion.charAt(navigator.appVersion.indexOf("(")+1) == "M"){
        is_mac = 1;
        }
if ((browserName == "Netscape" && browserVer >= 4)||((browserName == "Microsof" && browserVer == 3.01) && is_mac)||(browserName == "Microsof" && browserVer >= 4.0 && !is_mac)){
                if (!is_unix){
                browser_ok = 1;
                }
        }

if (browserName == "Netscape") {netscape = 1; proddescsize="x-small"};
if (browserName == "Microsof") {msie = 1; proddescsize="x-small"};

<!-- 	alert ("Soy "+browserName+" "+browserVer+"*"+navigator.appVersion+"* OK="+browser_ok); -->

if (!browser_ok) {
   document.write ("<body><br>"+
      "<table width=444 bgcolor='FFE6E6'><tr><td align='center'>"+
      "<br>Lamentablemente el navegador y/o la plataforma...<br><br>"+
      "<strong>"+browserName+" "+navigator.appVersion+"</strong>"+
      "<br><br>que está Vd. usando no se soportan por esta web"+
      "<br>para la consulta de dominios <em>on-line</em>"+
      "<br><br><hr>"+
      "<br>Unfortunately, your browser and/or the platform it is running on...<br><br>"+
      "<strong>"+browserName+" "+navigator.appVersion+"</strong>"+
      "<br><br>cannot be supported by this Web site"+
      "<br>for online querying domain names availability"+
      "<br><br>"+
      "</td></tr></table></body>");
   }
}

function ValidarEnvio(nombre) {
 if (!nomdomvalido(nombre)) {
   alert ("(E) Nombre de dominio inválido:  Consulte las normas de nombres de dominio");
   validname=false;
   return (false);
 }
 else {
   document.form.submit();
   validname=true;
   return (true);
 }
}

