function toggleImage(img) {
	img.active = !img.active;
	setImageState(img, img.active);
}
function setImageState(img, active) {
	// initialize image properties ...
	if (!img.activeImage) {
	    var activesrc = img.getAttribute? img.getAttribute('activesrc') : 
    		img.activesrc? img.activesrc : null;
    	
        img.activeImage = new Image();
        img.activeImage.src = activesrc;
        // normalImage might have already been initialized by oversrc.js
        if (!img.normalImage) {
            img.normalImage = new Image();
            img.normalImage.src = img.src;
        }
        img.normalTitle = img.title;
        img.activeTitle = img.getAttribute? img.getAttribute('activetitle') : 
    		img.activetitle? img.activetitle : null;
    	
    }
    img.src = active? img.activeImage.src : img.normalImage.src;
    if (img.activeTitle) {
    	img.title = active? img.activeTitle : img.normalTitle;
    }
    
}