JavaScript JS to determine whether the file exists __js

When you judge a client file, you can use the

var Fso,s=filespec; Filespec= "C:/path/myfile.txt"
Fso=new ActiveXObject ("Scripting.FileSystemObject");
if (FSO). FileExists (filespec))
s+= "exists."
Else
s+= "doesn ' t exist";
alert (s);

When judging server side (network file), you can use Var xmlhttp=new activexobject ("Microsoft.XMLHTTP");
Xmlhttp.open ("Get", yourfileurl,false);
Xmlhttp.send ();
if (xmlhttp.readystate==4) {
if (xmlhttp.status==200) s+= "exists."; URL exists
else if (xmlhttp.status==404) s+= "doesn ' t exist."; URL does not exist
else s+= "";/other State
}
alert (s);

You can <input style= "width:100%" type= "file" name= "id=" "contenteditable=" false > Set the contenteditable to False to restrict the user from selecting only files and not entering them casually.