<dropupload maxsize="5" detection="none" onUpload="" >
    <attribute name="content"><![CDATA[
        <b>Drop Here</b><br/>
        size < 5k
    ]]></attribute>
</dropupload>

    zk.fmt.Text.stuff = zk.fmt.Text.format;

	/**
	 * Formatting a filesize depending on its value:
	 * >= 1024 GB: 0.0 TB,
	 * >= 1024 MB: 0.0 GB,
	 * >= 1024 KB: 0.0 MB,
	 * >= 1024 B : 0.0 KB,
	 * else: bytes. Decimal point is determined by System language.
	 */
    zk.fmt.Text.formatFileSize = function (bytes) {
        var divider = 1024;

        if(Math.abs(bytes) < divider) {
            return bytes + msgzk.BYTES;
        }

        var units = [msgzk.KBYTES, msgzk.MBYTES, msgzk.GBYTES, msgzk.TBYTES]
        var unit = -1;

        do {
            bytes /= divider;
            ++unit;
        } while(Math.abs(bytes) >= divider && unit < units.length - 1);

        return +bytes.toFixed(1) + ' ' + units[unit];
    }

    zk.fmt.Text.format = function (msg) {
        if (msg == msgzul.UPLOAD_ERROR_EXCEED_MAXSIZE)
            return zk.fmt.Text.stuff(msg, zk.fmt.Text.formatFileSize(arguments[3]), zk.fmt.Text.formatFileSize(arguments[4]));
        else
            return zk.fmt.Text.stuff(arguments);
    }