function getOS() {
  var navigator = window.navigator;
  var os;
  if (navigator.platform.indexOf("Win32") != -1) {
    os = "windows";
  } else if (navigator.platform.indexOf("Linux") != -1) {
    os = "linux";
  } else if (navigator.userAgent.indexOf("Mac OS X") != -1) {
    os = "macosx";
  } else if (navigator.userAgent.indexOf("MSIE 5.2") != -1) {
    os = "macosx";
  }
  
  return os;
}

function getDefaultDistributionSuffix(os) {
  var suffix;
  if (os == "linux") {
    suffix = "linux-gtk.zip";
  } else if (os == "macosx") {
    suffix = "macosx-carbon.dmg";
  } else if (os == "windows") {
    suffix = "win32.msi";
  }
  return suffix;
}

function getHumanReadableOS(os) {
  var humanReadable;
  if (os == "linux") {
    humanReadable = "GNU/Linux";
  } else if (os == "macosx") {
    humanReadable = "Mac OS X";
  } else if (os == "windows") {
    humanReadable = "Windows";
  } else {
    humanReadable = "Unknown";
  }
  return humanReadable;
}

function toggleElementVisibility(elementId) {
	var element = document.getElementById(elementId);
	if ( element.style.display != 'none' ) {
		element.style.display = 'none';
	}
	else {
		element.style.display = '';
	}
}