// JScript 文件

//图片按比例缩放

var flag=false;

function DrawImage(ImgD, iw, ih)
{
	var image=new Image();
	var iwidth = iw; //定义允许图片宽度
	var iheight = ih; //定义允许图片高度
	image.src=ImgD.src;
	
	if(image.width > 0 && image.height > 0)
	{
		flag=true;
		
		if(image.width/image.height >= iwidth/iheight)
		{
			if(image.width > iwidth)
			{ 
				ImgD.width=iwidth;
				ImgD.height = (image.height * iwidth) / image.width;
			}
			else
			{
				ImgD.width=image.width; 
				ImgD.height=image.height;
			}

			//ImgD.alt=image.width+"×"+image.height;
		}
		else
		{
			if(image.height > iheight)
			{ 
				ImgD.height = iheight;
				ImgD.width = (image.width * iheight) / image.height; 
			}
			else
			{
				ImgD.width = image.width; 
				ImgD.height = image.height;
			}
			
			//ImgD.alt=image.width + "×" + image.height;
		}
	}
} 
//调用：<img src="图片" onload="javascript:DrawImage(this, iw, ih)">