I'v done a tree view in xsl using a javascript function I want to change the icons depending on the status (+ for to open , - for to close)
This questions is as clear as thick molasses in a pool of mud. (Will try to answer, though.)
I assume you mean XML stylesheets with xsl. If you meant Excel, it should have been xls. But let's assume you mean stylesheets and you're using it to generate a webpage which contains a treeview. In this treeview there are icons indicating if the node is expanded or not. If expanded, display +, else display -. Am I right, here?
Now, it depends on how you've implemented this treeview in your stylesheet. The most practical way would be to just send the tree data fully expanded to the page and let the Javascript handle this client-side. In that case, all you need to know is how to expand and collapse nodes in Javascript with the additional icon change.
Another possible implementation would be when expanding and collapsing is done serverside, thus you'd only send the visible data. In that case you can also just tell the page which icon to use and there would be no need for any javascript. The icon would just be a link back to the server, updating the data through a new requests which builds a new webpage.
A third option would be the WEB 2.0 solution, where you just send the list as a collapsed treeview and every time the user clicks an icon, a AJAX event gets triggered, collecing the additional node data and changing the icon of the treenode.
These are three very different techniques and they're not always the best solution. The first solution is a problem when dealing with lots of data in your tree. It needs to load it all. The second option will generate a lot more traffic with the server but handles better with large amounts of data because you only display the open node. The third option is a bit of a mixture between the first two options. You don't need all data from the beginning and you're not recreating the webpage over and over again. But it's also more complex to code.
Now, I wonder which of these options you use. Once we know this, we can help you. (Edit your question to provide this information and perhaps even add the JavaScript tag to it.)
To be honest, xsl is only used to change the shape of an XML document and it knows nothing about treeviews or whatever. So I don't see any link between xsl and treeviews. It's just that you use xsl to transform your data into something that some Javascript library can process as a treeview. Which Javascript library is this?