// Determine browser type (Netscape 6 or IE 5.5/6.0).

var isIE5 = (navigator.userAgent.indexOf("MSIE 5.5") > 0	|
						 navigator.userAgent.indexOf("MSIE 6.0") > 0) ? 1 : 0;
var isNS6 = (navigator.userAgent.indexOf("Gecko")		> 0) ? 1 : 0;

// For IE, adjust menu bar styling.

if (isIE5) {
	document.styleSheets[document.styleSheets.length - 1].addRule("#menuBar", "padding-top:4px");
	document.styleSheets[document.styleSheets.length - 1].addRule("#menuBar", "padding-bottom:3px");
}

// Global variable for tracking the currently active button.

var activeButton = null;

// Capture mouse clicks on the page so any active button can be deactivated.

if (isIE5)
	document.onmousedown = pageMousedown;
if (isNS6)
	document.addEventListener("mousedown", pageMousedown, true);

function pageMousedown(event) {

	var className;

	// If the object clicked on was not a menu button or item, close any active
	// menu.

	if (isIE5)
		className = window.event.srcElement.className;
	if (isNS6)
		className = (event.target.className ?
			event.target.className : event.target.parentNode.className);

	if (className != "menuButton" && className != "menuItem" && activeButton)
		resetButton(activeButton);
}

//********************************************************//
function buttonClick(button, menuName) {
//********************************************************//

	// Blur focus from the link to remove that annoying outline.

	button.blur();

	// Associate the named menu to this button if not already done.

	if (!button.menu)
		button.menu = document.getElementById(menuName);

	// Reset the currently active button, if any.

	if (activeButton && activeButton != button)
		resetButton(activeButton);

	// Toggle the button's state.

	if (button.isDepressed)
		resetButton(button);
	else
		depressButton(button);

	return false;
}

//********************************************************//
function buttonMouseover(button, menuName) {
//********************************************************//

	// If any other button menu is active, deactivate it and activate this one.
	// Note: if this button has no menu, leave the active menu alone.

	if (activeButton && activeButton != button) {
		resetButton(activeButton);
		if (menuName)
			buttonClick(button, menuName);
	}
}

//********************************************************//
function depressButton(button) {
//********************************************************//

	// Save current style values so they can be restored later.
	// Only needs to be done once.

	if (!button.oldBackgroundColor) {
		button.oldBackgroundColor = button.style.backgroundColor;
		button.oldBorderBottomColor = button.style.borderBottomColor;
		button.oldBorderRightColor = button.style.borderRightColor;
		button.oldBorderTopColor = button.style.borderTopColor;
		button.oldBorderLeftColor = button.style.borderLeftColor;
		button.oldColor = button.style.color;
		button.oldLeft = button.style.left;
		button.oldPosition = button.style.position;
		button.oldTop = button.style.top;
	}

	// Change style value to make the button looks like it's
	// depressed.

	//button.style.backgroundColor = "#4A4A4A";
	//button.style.borderBottomColor = "#4A4A4A";
	//button.style.borderRightColor = "#4A4A4A";
	//button.style.borderTopColor = "#4A4A4A";
	//button.style.borderLeftColor = "#4A4A4A";
	button.style.color = "black";
	button.style.left = "1px";
	button.style.position = "relative";
	button.style.top = "1px";

	// For IE, force first menu item to the width of the parent menu,
	// this causes mouseovers work for all items even when cursor is
	// not over the link text.

	if (isIE5 && !button.menu.firstChild.style.width)
		button.menu.firstChild.style.width =
			button.menu.offsetWidth + "px";

	// Position the associated drop down menu under the button and
	// show it. Note that the position must be adjusted according to
	// browser, styling and positioning.

	x = getPageOffsetLeft(button);
	y = getPageOffsetTop(button) + button.offsetHeight;
	if (isIE5)
		y += 2;
	if (isNS6) {
		x--
		y--
	}
	button.menu.style.left = x + "px";
	button.menu.style.top	= y + "px";
	button.menu.style.visibility = "visible";

	// Set button state and let the world know which button is
	// active.

	button.isDepressed = true;
	activeButton = button;
}

//********************************************************//
function resetButton(button) {
//********************************************************//

	// Restore the button's style settings.

	button.style.backgroundColor = button.oldBackgroundColor;
	button.style.borderBottomColor = button.oldBorderBottomColor;
	button.style.borderRightColor = button.oldBorderRightColor;
	button.style.borderTopColor = button.oldBorderTopColor;
	button.style.borderLeftColor = button.oldBorderLeftColor;
	button.style.color = button.oldColor;
	button.style.left = button.oldLeft;
	button.style.position = button.oldPosition;
	button.style.top = button.oldTop;

	// Hide the button's menu.

	if (button.menu)
		button.menu.style.visibility = "hidden";

	// Set button state and clear active menu global.

	button.isDepressed = false;
	activeButton = null;
}

//********************************************************//
function getPageOffsetLeft(el) {
//********************************************************//

	// Return the true x coordinate of an element relative to the page.

	return el.offsetLeft + (el.offsetParent ? getPageOffsetLeft(el.offsetParent) : 0);
}

//********************************************************//
function getPageOffsetTop(el) {
//********************************************************//

	// Return the true y coordinate of an element relative to the page.

	return el.offsetTop + (el.offsetParent ? getPageOffsetTop(el.offsetParent) : 0);
}