Upload image form:

<form name="frmzsimg" enctype="multipart/form-data" method="post" action="upimage.asp">
    <INPUT type=file name=image>
    <input type="submit" name="Submit" value="Ìá½»">
</form>

want to limit the size of image within 50k in a vbscript sub:

<SCRIPT LANGUAGE="VBScript">
    Sub frmzsimg_onsubmit
    ......
    end sub
</SCRIPT>

how to write this vbs~~~~??~