The blur() method is used to remove focus from the FileUpload box.
<html>
<head>
<title>Using the blur() method of the FileUpload object</title>
</head>
<body>
<script language="JavaScript">
<!--
function showMessage(){
document.form1.uploadbox.blur();
document.form1.textbox.value = "File Submitted";
}
-->
</script>
<form name="form1">
Enter Filename:
<input type="file" name="uploadbox">
<input type="button" value="Okay" onClick=showMessage()>
<br><br>
Confirmation:
<input type="text" name="textbox">
</form>
</body>
</html>