for (i=0;i<document.images.length;i++)
{
    if(document.images[i].style.styleFloat == "left" || document.images[i].style.cssFloat == "left")
    {
        document.images[i].style.marginRight = "10px";
        document.images[i].style.marginLeft = "0px";
    }
    else if(document.images[i].style.styleFloat == "right" || document.images[i].style.cssFloat == "right")
    {
        document.images[i].style.marginRight = "0px";
        document.images[i].style.marginLeft = "10px";
    }
}