javascript兑现另存为对话框 _JavaScript

javascript实现另存为对话框

<html>
 <head>
  <title> New Document </title>
  <meta name="Generator" content="EditPlus">
  <meta name="Author" content="">
  <meta name="Keywords" content="">
  <meta name="Description" content="">
  <script src="jquery-1.3.js" type="text/javascript"></script>
  <script language="JavaScript">
  <!--
    function downLoadImage(imagePathURL){
	
        //如果中间IFRAME不存在，则添加
        if(!document.getElementById("_SAVEASIMAGE_TEMP_FRAME"))
            $('<iframe style="display:none;" id="_SAVEASIMAGE_TEMP_FRAME" name="_SAVEASIMAGE_TEMP_FRAME" onload="_doSaveAsImage();" width="0" height="0" src="about:blank"></iframe>').appendTo("body");        
        
        if(document.all._SAVEASIMAGE_TEMP_FRAME.src!=imagePathURL){
            //图片地址发生变化，加载图片
            document.all._SAVEASIMAGE_TEMP_FRAME.src = imagePathURL;
        }else{
            //图片地址没有变化，直接另存为
            _doSaveAsImage();
        }
    }
    function _doSaveAsImage(){
        if(document.all._SAVEASIMAGE_TEMP_FRAME.src!="about:blank")
            document.getElementById('_SAVEASIMAGE_TEMP_FRAME').document.execCommand("SaveAs");        
    }

  //-->
  </script>
 </head>

 <body>
  <input type="button" value="download image" onclick="downLoadImage('r_beyond1991.jpg');">  
 </body>
</html>

<input   type="button"   value="保存"   onclick="document.execCommand('SaveAs')">   
<input   type="button"   value="另存为"   onclick="document.execCommand('SaveAs',false,'c:\\oak.htm')">