让图片自适应外DIV 而不是拉伸的方法

#ulRecomList img{max-width:170px; max-height:127px;display:inline !important;
                 scale:expression((this.offsetWidth > this.offsetHeight)?(this.style.width = this.offsetWidth >= 170 ? "170px" : "auto"):(this.style.height = this.offsetHeight >= 127 ? "127px" : "auto")); 
                 background-image:url(/images/cardetailphoto/process.gif) no-repeat ; }