function DrawImage(obj,setW,setH) {
	
		divW = obj.width;
		divH = obj.height;
	
	if (divH < setH) {//以设置高为准
				obj.style.marginTop = parseInt((setH - divH) / 2) + "px";
			}else if (divH > setH) {
				val = setW - setH >= 0?setH:setW;
				obj.style.width = obj.style.height = val + "px";
				if (setH > val) {
					obj.style.marginTop = parseInt((setH - val) / 2) + "px";
				}
			}
	
	if (divW > divH) {//以图片宽为准
			if (divW > setW) {
				valW = setW;
				valH = parseInt(setW * divH / divW);		
				if (valH > setH) {
					valH = setH;
					valW = parseInt(setH * valW / valH);	
				}
				obj.style.width = valW + "px";
				obj.style.height = valH + "px";
				obj.style.marginTop = parseInt((setH - valH) / 2) + "px";
			}
	
	}else if (divH > divW) {//以图片高为准
			if (divH > setH) {
				valH = setH;
				valW = parseInt(setH * divW / divH);		
				if (valW > setW) {
					valW = setW;
					valH = parseInt(setW * valH / valW);	
				}
				obj.style.height = valH + "px";
				obj.style.width = valW + "px";
		}
	}
}