Ok, I've red all threads about it on the board and nothing works, here's my code for the rollover:

Code:
function change_image_layer(image_name, image_src, layer_name)
{

    // Can the browser handle rollovers?
    if (document.images)
    {
        // Is is a DOM-compatible browser?? (Netscape4.x below are NOT)
        if (document.layers)
        {
            // MUST FIX N4.x
            document.layers[layer_name].document.images[image_name].src = image_src;
        }
        else
        {
            document.images[image_name].src = image_src;
        }
    }

}
Let's say my image is called "submenu2_1" and is within the layer/div "subnav2", here's the code I put :

Code:
onMouseOver="change_image_layer('submenu2_1','images/submenu2_1_on.gif','subnav2'); return true;" onMouseOut="change_image_layer('submenu2_1','images/submenu2_1.gif','subnav2'); return true;"
Now Netscape 4.7 gives me the following error : document.layers[layer_name]

Please help!

Thanks