//调用方式<img src='"+url+"' onload='javascript:DrawImage(this,300,380)'>

//图片按比例缩放

var flag=false;
function DrawImage(ImgD,iwidth,iheight){
    //参数(图片,允许的宽度,允许的高度)
    var image=new Image();
    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;
        }
    }
}
//察看已经上传得图片

function showpic(url,divname){
var obj=document.getElementById(divname);
  document.all(divname).style.display="block";
  obj.innerHTML="<img src='"+url+"' onload='javascript:DrawImage(this,300,380)'><br><a href='#' onClick='javascrpt:closeshowpic();'>关闭</a>";
}
function closeshowpic()
{
document.all("lookuppic").style.display="none";
}

//验证上传图片大小,文件域中调用,例如：onchange(this,2)；

//files:file对象
//maxSizes 单位：M
function checkSize(files,maxSizes)  
{    
	var maxsize = maxSizes*1024;
 	var fso,f;  
  	fso=new ActiveXObject("Scripting.FileSystemObject");  
  	f=fso.GetFile(files.value);
  	var mySize = f.size/1024;
  	if(mySize>maxsize){
  		alert("您上传的文件太大!");
  		files.select();
  		document.execCommand('Delete');
  		return ;
  	} 
}