<Form> <p align="center">Gulden <input type="text" name="gulden" onKeyUp="this.form.euro.value=Math.round(this.value / 0.0220371)/100 " size="8"> Euro<input type="text" name="euro" onKeyUp="this.form.gulden.value=Math.round(this.value * 220.3710)/100 " size="8"> </Form>