<!--hide this script from non-javascript-enabled browsers

//////////////////////////////////////////////////////////
//
// Rollover.js
//
// Produced by Presenting Science
//  www.PresentingScience.com
//
// Copyright (C) Presenting Science 2001
//
//////////////////////////////////////////////////////////

var bHasActiveImage = false;		// If not set, then no active image is preserved

// Simple object to hold a two-state image
function DynamicImage(passive, over, active) {
	this.passiveImage = new Image();	this.passiveImage.src = passive;
	this.overImage = new Image();		this.overImage.src = over;
	this.activeImage = new Image();		this.activeImage.src = active;
}

// Called on mouse over - set bold image
function mouseOver(imageName, status) {
    var currentSection = bHasActiveImage ? getActiveImage() : "";
    if (document.images[imageName] && dynamicImages && imageName != currentSection) {
        document.images[imageName].src = dynamicImages[imageName].overImage.src;
    }
    window.status = status;
    return true;
}

// Called on mouse out - revert to standard image
function mouseOut(imageName) {
    var currentSection = bHasActiveImage ? getActiveImage() : "";
    if (document.images[imageName] && dynamicImages && imageName != currentSection) {
        document.images[imageName].src = dynamicImages[imageName].passiveImage.src;
    }

    window.status = '';
    return true;
}


// Set the active index from a cookie
function setActiveImage(imageName) {
    bHasActiveImage = true;
    document.cookie = "activeImage="+imageName;
    // Loop over the document's images, checking that they're consistent with this active image
    if (document.images && dynamicImages) {
        for (i=0;i<document.images.length;i++)					// Loop over all doc's images
            if (dynamicImages[document.images[i].name])			// If a correspoding dynamicImage exists...
                document.images[i].src = (document.images[i].name==imageName)? // Does its name equal the new active one?
                    dynamicImages[document.images[i].name].activeImage.src :	// Then set the active image
                    dynamicImages[document.images[i].name].passiveImage.src ; // Else restore the passive one
    }
}

// Store the name of the active image in a cookie - Refresh proof!
function getActiveImage() {
    var value = "";
    var pos = document.cookie.indexOf("activeImage=");
    if (pos != -1) {
        var start = pos+12;
        var end = document.cookie.indexOf(";", start);
        if (end == -1) end = document.cookie.length;
        value = document.cookie.substring(start, end);
    }
    return value;
}

// Usually called on load to activate a default image
function resetActiveImage(defaultActive) {
    var lastActive = getActiveImage();
    if (lastActive=="") lastActive = defaultActive;
    setActiveImage(lastActive);
}

// stop hiding -->