function resize(myImg,maxWidth,maxHeight){
	var iniPicWidth = myImg.width;
	var iniPicHeight = myImg.height;
	var iniRate = iniPicHeight/iniPicWidth;

	if(iniPicWidth>maxWidth || iniPicHeight>maxHeight){
		var newW = maxWidth;
		var newH = Math.floor(newW*iniRate);
		if (newH>maxHeight){
			newH = maxHeight;
			newW = Math.floor(newH/iniRate);
		}
		myImg.width = newW;
		myImg.height = newH;
	}
}