用fso对象判断一下:
<SCRIPT LANGUAGE="JavaScript">
<!--
function checksize(filename){
if(form1.aa.value!="")
{
var fso=new ActiveXObject("scripting.filesystemobject");
f=fso.GetFile(filename);
alert("文件大小为:"+f.size/1000+"KB");
}else{
alert("文件不能为空!");return false;
}
}
//-->
</SCRIPT>
<form name=form1 onsubmit="checksize(aa.value)">
<INPUT TYPE="file" NAME="aa">
<input type=submit>
</form>
<SCRIPT LANGUAGE="JavaScript">
<!--
function checksize(filename){
if(form1.aa.value!="")
{
var fso=new ActiveXObject("scripting.filesystemobject");
f=fso.GetFile(filename);
alert("文件大小为:"+f.size/1000+"KB");
}else{
alert("文件不能为空!");return false;
}
}
//-->
</SCRIPT>
<form name=form1 onsubmit="checksize(aa.value)">
<INPUT TYPE="file" NAME="aa">
<input type=submit>
</form>
imgMaxSize=100; //图片文件最大多少K
var img=null;
img=document.createElement("img");
if((img.fileSize/1024)>imgMaxSize)
{
alert("您所要上传的图片超过"+imgMaxSize+"K");
return false;
}
imgMaxSize=100; //图片文件最大多少K
var img=null;
function chkimg(inp)
{
if(img)img.removeNode(true);
img=document.createElement("img");
img.attachEvent("onreadystatechange",isimg);
img.attachEvent("onerror",notimg);
img.src=inp;
if((img.fileSize/1024)>imgMaxSize)
{
alert("您所要上传的图片超过"+imgMaxSize+"K");
return false;
}
}
<input type='file' name='images' onsubmit="chkimg(this.value)">