function setOpacity(img_id) {
	var img  = document.getElementById("tm_image_" + img_id);
	var blah = img.className;
	
	
	//alert(blah);
	
	if(blah == "opacityOn") {
		img.className = "opacityOff";
	}
	
	if(blah == "opacityOff") {
		img.className = "opacityOn";
	}
}