var Browser = {
  Version: function() {
    var version = 999;
    if (navigator.appVersion.indexOf("MSIE") != -1)
	version = parseFloat(navigator.appVersion.split("MSIE")[1]);
    return version;
  }
}

if (Browser.Version() < 7) {
  if (window.location.href != "old-version") {
    window.location.href = "old-version";
  }
}