javascript 上传文件大小限定

js 上

限制： < input type = " text "  size = " 4 "  value = " 10 "  name = " fileSizeLimit "  id = " fileSizeLimit " />  K
< input type = " file "  name = " file1 "  id = " file1 "  size = " 40 "  onchange = " changeSrc(this) " />
< br >
< img src = http: // blog.xunuo.com/blog/images/icons/23.gif id="fileChecker" alt="test"/>

< script type = " text/javascript " >
var  oFileChecker  =  document.getElementById( " fileChecker " );

function  changeSrc(filePicker)
{
    oFileChecker.src  =  filePicker.value;
}

oFileChecker.onreadystatechange  =   function  ()
{
     if  (oFileChecker.readyState  ==   " complete " )
    {
        checkSize();
    }
}

function  checkSize()
{
     var  limit   =  document.getElementById( " fileSizeLimit " ).value  *   1024 ;

     if  (oFileChecker.fileSize  >  limit)
    {
        alert( " too large " );
    }
     else
    {
        alert( " ok " );
    }
}
</ script >   

IE

< html >  
< input type = " file "  name = " file1 "  onchange = " ShowSize(this.value) " >  
< script language = " JavaScript " >  
<!--  
function  ShowSize(files) 
{ 
   var  fso,f; 
  fso = new  ActiveXObject( " Scripting.FileSystemObject " ); 
  f = fso.GetFile(files); 
  alert( (f.size / ( 1024 * 1024 )) + "  Bytes " ); 
} 
// --> 
</ script >  
</ html >