var BigImageYOffSet = -51;
    function showimgById(id,YOffsett)
    {
        var obj = GetElement(id);
        roll_over(obj,YOffsett);
    }
    function roll_over(imgtag,YOffsett)
    {
    if (YOffsett == null) YOffsett =0;
         obj = GetElement('BigImg');
         obj.src = imgtag.src;
         var top = getY(imgtag)+BigImageYOffSet+YOffsett;
         obj.style.top = top+"px";
         var floatdir = imgtag.style.styleFloat;
         if (floatdir == undefined) floatdir = imgtag.style.cssFloat;
         if (floatdir  != "left")
         {
            obj.style.right = null;
            obj.style.left = "18px";
         }
         else
         {
            obj.style.right = "18px";
            obj.style.left = null;
         }
        obj.style.visibility  = "visible"
    }
    function roll_out()
    {
         var obj = GetElement('BigImg');
         obj.src = "";
         obj.style.visibility  = "hidden"
    }

    function getY( oElement )
    {
        var iReturnValue = 0;
        while( oElement != null ) 
        {
            iReturnValue += oElement.offsetTop;
            oElement = oElement.offsetParent;
        }
        return iReturnValue;
    }