var imgIDs = [
    ['imgwin0', 'imgs0'],
    ['imgwin1', 'imgs1'],
    ['imgwin2', 'imgs2']
];

for(var i = 0 ; i < imgIDs.length ; i++ ) {
    var imgs = $(imgIDs[i][1]).getElementsByTagName('img');
    for(var j = 0 ; j < imgs.length ; j++) {
        imgs[j].onmouseover = new Function ('','$("' + imgIDs[i][0] + '").src = this.src;');
    }
}