function resizeImage(obj,size)  
{  
    if(obj.width>obj.height)
    {
        obj.width=size;
        var gap = (obj.width - obj.height) / 2;
        obj.style.paddingTop=gap+"px";
        obj.style.paddingBottom=gap+"px";
    }else{
        obj.height=size;
        var gap = (obj.height - obj.width) / 2;
        obj.style.paddingLeft=gap+"px";
        obj.style.paddingRight=gap+"px";
    }
}