Syntax
onFocus="command"
The onFocus event handler notifies you when the focus is set on the upload box.
<html>
<head>
<title>Using the onFocus event handler</title>
</head>
<body>
<script language="JavaScript">
<!--
function showMsg1(){
document.form1.msg.value += "Focus on the FileUpload box\n";
}
function showMsg2(){
document.form1.msg.value += "Focus removed from FileUpload box\n";
}
-->
</script>
<form name="form1">
Click in the FileUpload box to set focus to it.
<br><br>
<input type="file" name="uploadbox" onFocus = 'showMsg1()'>
<br><br>
Click on the button to remove focus from the FileUpload box.
<br>
<input type="button" value="Click here" onClick='showMsg2()'>
<br><br>
<textarea name="msg" rows="5" cols="50"></textarea>
</form>
</body>
</html>