function gengo_language_remove(id) {

	$('gengo_available_languages').appendChild(document.getElementById('gengo_language_' + id));

	$('gengo_control_set_' + id).innerHTML = '<a class="gengo_element_control" href="#" onclick="return gengo_language_add(' + id + ');">' + add_message + '</a>';

	return false;

}



function gengo_language_add(id) {

  var node = document.getElementById('gengo_language_' + id)

	$('gengo_viewing_languages').appendChild(node);

	$('gengo_control_set_' + id).innerHTML = '<a class="gengo_element_control" name="up" href="#" onclick="return gengo_language_move_up(' + id + ');">' + up_message + '</a> <a class="gengo_element_control" href="#" onclick="return gengo_language_move_down(' + id + ');">' + down_message + '</a> <a class="gengo_element_control" href="#" onclick="return gengo_language_remove(' + id + ');">' + x_message + '</a>';

	return false;

}



// gengo_create_cookie modified from code found at quirksmode.org

function gengo_create_cookie(name, value) {

	var date = new Date();

	date.setTime(date.getTime() + 30000000);

	var expires = "; expires=" + date.toGMTString();

	document.cookie = name + "=" + value + expires + "; path=" + cookie_path;

}



function gengo_language_save() {

  var nodes = $('gengo_viewing_languages').childNodes;

	var code_string = '';

	var relocation_string = '';

	for (var i = 0; i < nodes.length; i++) {

    if (nodes[i].tagName == 'LI') {

			var id = nodes[i].id.substr('gengo_language_'.length);

			if (code_string != '') code_string += encoded_divider;

			if (relocation_string != '') relocation_string += language_divider;

			code_string += language_codes[id];

			relocation_string += language_codes[id];

		}

	}

	if ('' == code_string) {

		alert(save_error_message);

	} else {

		gengo_create_cookie(cookie_name, code_string);

		window.location = site_home + '/' + relocation_string + '/';

	}

	return false;

}



function gengo_language_reset() {

  var viewable_codes = original_codes.split(language_divider);

  var other_codes = viewable_codes.diff(language_codes);

	var language_id;

	for (var i = 0; i < viewable_codes.length; i++) {

		language_id = language_ids[viewable_codes[i]];

		gengo_language_add(language_id);

	}

	for (var i = 0; i < other_codes.length; i++) {

		language_id = language_ids[other_codes[i]];

		gengo_language_remove(language_id);

	}

	return false;

}



function gengo_switch_summary(summary_id) {

	if (current_id == summary_id) return false;

	$('gengo_summary_' + current_id).style.display = 'none';

	$('gengo_summary_' + summary_id).style.display = 'block';

	current_id = summary_id;

}



// From: http://www.mozilla.org/docs/dom/technote/whitespace/

function is_all_ws(nod) {

  return !(/[^\t\n\r ]/.test(nod.data));

}



function is_ignorable(nod) {

  return (nod.nodeType == 8) || ((nod.nodeType == 3) && is_all_ws(nod));

}



function findPrevNode(node) {

  while ((node = node.previousSibling)) {

    if (!is_ignorable(node)) return node;

  }

  return null;

}



function findNextNode(node) {

  while ((node = node.nextSibling)) {

    if (!is_ignorable(node)) return node;

  }

  return null;

}



// from: http://www.xs4all.nl/~zanstra/logs/jsLog.htm

function DOMNode_swapNode(n1,n2) {

  n1.parentNode.insertBefore(n2.parentNode.removeChild(n2),n1);

}



function gengo_language_move_up(id) {

  var node = $('gengo_language_' + id);

  var previous_node = findPrevNode(node);

  if (previous_node) {

   DOMNode_swapNode(previous_node, node);

 	}

	return false;

}



function gengo_language_move_down(id) {

  var node = $('gengo_language_' + id);

  var next_node = findNextNode(node);

  if (next_node) {

    DOMNode_swapNode(node, next_node);

  }

	return false;

}