function dispInstructions() {
	var elem = document.getElementById("instructionsList");
	elem.style.display = "block";
}

function hideInstructions() {
	var elem = document.getElementById("instructionsList");
	elem.style.display = "none";
}

// given a node in the DOM, retrieve its parent with a className "entry", 
// if such a parent exists.
function getParentEntry(elem) {
	return getParentWithClassName(elem, "entry");
}

function getParentWithClassName(elem, name) {
	return getParentWithClassName(elem, name, 0);
}

function getParentWithClassName(elem, name, strict) {
	var entryElem = elem;
	if (strict == 1) {
		entryElem = elem.parentNode;
	}
	if (entryElem && entryElem.className != name) {
		while (entryElem && entryElem.className != name) {
			entryElem = entryElem.parentNode;	
		}
	}
	return entryElem;
}


function highlight(elem) {
	
	var entry = getParentWithClassName(elem, "entryLine");
	
	
	
	if (highlighted && highlighted != entry) {
		highlighted.style.background = "none";
	}
	
	if (highlighted != entry) {
		if (curEdit) {
			submitEdit(curEdit);
		}
		// now we need the "entryLine" span inside.
		entry.style.background = highlightColor;
		highlighted = entry;
		
		// change the font menu to reflect the current settings.
		var fontMenu = document.getElementById("fontFamily");
		
		
		var fontElem = entry;
		fontName = fontElem.style.fontFamily;
		while (fontElem && !fontName) {
			fontElem = fontElem.parentNode;
			if (fontElem && fontElem.style)
				fontName = fontElem.style.fontFamily;
		}
		
		//alert(fontMenu.options.length);
		if (fontName) 
			fontFamily = fontName;
		else
			fontFamily = defaultFontFamily;
		for (var i=0; i < fontMenu.options.length; i++) {
			//alert(fontMenu.options[i].value + ": " + entry.style.fontFamily);

			if (fontFamily == fontMenu.options[i].value) {
				//fontFamily = fontName;
				fontMenu.options[i].selected = "selected";
				return;
			}
		}
			
		
	}
}


// creates a new button input element
function createButton(buttonName, onclick) {
	var but = document.createElement("input");
	but.setAttribute("type", "button");
	but.setAttribute("name", buttonName);
	but.setAttribute("value", buttonName);
	but.setAttribute("onclick", onclick);
	return but;
}

// creates a new image element
function createImage(path, alt, onclick) {
	var img = document.createElement("img");
	img.src = path;
	img.setAttribute("alt", alt);
	img.setAttribute("onclick", onclick);
	return img;
}


// ------------------- BORROWED CODE ------------------


// drag and drop code adapted from: http://brainjar.com/dhtml/drag/ 

// Global object to hold drag information.

var dragObj = new Object();
dragObj.zIndex = 0;

function dragStart(event, id) {

  var el;
  var x, y;

  // If an element id was given, find it. Otherwise use the element being
  // clicked on.

  if (id)
    dragObj.elNode = document.getElementById(id);
  else {
    
      dragObj.elNode = event.target;

    // If this is a text node, use its parent element.

    if (dragObj.elNode.nodeType == 3)
      dragObj.elNode = dragObj.elNode.parentNode;
  }

  // Get cursor position with respect to the page.

    x = event.clientX + window.scrollX;
    y = event.clientY + window.scrollY;

  // Save starting positions of cursor and element.

  dragObj.cursorStartX = x;
  dragObj.cursorStartY = y;
  dragObj.elStartLeft  = parseInt(dragObj.elNode.style.left, 10);
  dragObj.elStartTop   = parseInt(dragObj.elNode.style.top,  10);

  if (isNaN(dragObj.elStartLeft)) dragObj.elStartLeft = 0;
  if (isNaN(dragObj.elStartTop))  dragObj.elStartTop  = 0;

  // Update element's z-index.

  dragObj.elNode.style.zIndex = ++dragObj.zIndex;

  // Capture mousemove and mouseup events on the page.

    document.addEventListener("mousemove", dragGo,   true);
    document.addEventListener("mouseup",   dragStop, true);
    event.preventDefault();
  
}

function dragGo(event) {

  var x, y;

  // Get cursor position with respect to the page.

    x = event.clientX + window.scrollX;
    y = event.clientY + window.scrollY;

  // Move drag element by the same amount the cursor has moved.

  dragObj.elNode.style.left = (dragObj.elStartLeft + x - dragObj.cursorStartX) + "px";
  dragObj.elNode.style.top  = (dragObj.elStartTop  + y - dragObj.cursorStartY) + "px";

    event.preventDefault();
}

function dragStop(event) {

  // Stop capturing mousemove and mouseup events.

    document.removeEventListener("mousemove", dragGo,   true);
    document.removeEventListener("mouseup",   dragStop, true);
}

 

// end drag and drop code.

// code for this function inspired by:
// http://www.jennifermadden.com/162/examples/stringEnterKeyDetector.html
function checkEnter(event, elem) {
	var key;
	if (event.which) 
		key = event.which;
	else if (event.keyCode) 
		key = event.keyCode;
	
	if (key) {
		if (key == 13) {
			submitEdit(curEdit);
			event.cancelBubble = true;
			return false;
		} else if (key != 0) {
			//var len = elem.getAttribute("size");
			var mySize = elem.value.length + 2;
			if (mySize > 90) {
				mySize = 90;
			}
			elem.setAttribute("size", mySize);
		}
	}
	event.cancelBubble = true;
	
	return false;
}

// Hierarchy expand/collapse code:

// code for this function taken from example code from class
function hideChildren(parentElem) {
	if(parentElem.hasChildNodes()) {
		for (var i=0; i < parentElem.childNodes.length; i++) {
			if (parentElem.childNodes[i].nodeName == "DIV" && parentElem.childNodes[i].className == "entry") {
				parentElem.childNodes[i].style.display="none";
			}
		}
	}
}

// code for this function taken from example code from class
function showChildren(parentElem) {
	if(parentElem.hasChildNodes()) {
		for (var i=0; i < parentElem.childNodes.length; i++)
			if (parentElem.childNodes[i].nodeName == "DIV" && parentElem.childNodes[i].className == "entry") {
				parentElem.childNodes[i].style.display="block";
			}
	}
}

// code for this function taken from example code from class

var closedSrc = "images/plus.gif"
var openSrc = "images/minus.gif"

function toggleChildren(imageElem) {
	//var parentElem = imageElem.parentNode;
	var parentElem = getParentEntry(imageElem);
	if (parentElem.nodesDisplayed) {
		openSrc = imageElem.src;
		imageElem.src = closedSrc;
		hideChildren(parentElem);
		parentElem.nodesDisplayed = false;
	} else {
		closedSrc = imageElem.src;
		imageElem.src = openSrc;
		showChildren(parentElem);
		parentElem.nodesDisplayed = true;
	}
}