window.onload = preloadImages;

var imageNames = new Array('whatwedo_s.jpg', 'clothcalc_s.jpg', 'collection_s.jpg', 'corporate_s.jpg', 'contact_s.jpg');
var nImages = new Array();
var oImages = new Array();


function preloadImages()
{
    for (var i = 0; i < imageNames.length; i++)
    {
        nImages['menuimg'+i]  = new Image();
        if (i == imageNames.length-1) nImages['menuimg'+i].onload = registerOver;
        nImages['menuimg'+i].src = 'images/menu/'+imageNames[i];
        oImages['menuimg'+i] = document.getElementById('menuimg'+i).src;
    }
}

function registerOver()
{
    for (var i = 0; document.getElementById('menuimg'+i); i++)
    {
        var element = document.getElementById('menuimg'+i);
        element.onmouseover = function () { this.src = nImages[this.id].src; }
        element.onmouseout = function () { this.src = oImages[this.id]; }
    }  
}