I just experimented with onmouseover handler of FlyTreeView this seems to work as you request:
var plusPattern = \"QpWltnU83g_zM570\";
var plusHoverUrl = \"/test/img/hover_plus.gif\";
var minusPattern = \"Fy55sb6maSj0\";
var minusHoverUrl = \"/test/img/hover_minus.gif\";
function handleFTVOver(event)
{
var srcElement = event.target ? event.target : event.srcElement;
proceedElementHover(srcElement, plusPattern, plusHoverUrl);
proceedElementHover(srcElement, minusPattern, minusHoverUrl);
}
function proceedElementHover(element, testPattern, hoverUrl)
{
if (element.tagName == \"IMG\" && element.src.indexOf(testPattern) != -1)
{
var originalSrc = element.src;
element.src = hoverUrl;
var hoverSrc = element.src;
element.onmouseout = function() { if (hoverSrc == element.src) element.src = originalSrc; };
}
}
All you need is to change plusPattern, plusHoverUrl, minusPattern and minusHoverUrl to your values.