过渡到简单的JavaScript幻灯片

Question

嘿伙计们，我在寻找一种简单的方法来添加转换到一个非常基本的javascript图像幻灯片时遇到了一些麻烦：

//variable that will increment through the images
var step=1
var whichimage=1
function slideit(){
    //if browser does not support the image object, exit.
    if (!document.images)
        return
    document.images.slide.src=eval('image'+step+'.src')
    whichimage=step
    if (step<3)
        step++
    else
        step=1
    //call function 'slideit()' every 5 seconds
    setTimeout('slideit()',5000)
}
slideit()
function slidelink(){
    if (whichimage==1)
        window.location='page1.php'
    else if (whichimage==2)
        window.location='page1.php'
    else if (whichimage==3)
        window.location='index.php'
}

如何添加淡入或滑动过渡？