<!-- hide script from old browsers
function berekenhardheid()
{
//------------------------------------------------------------
// Script by Jasper Elgersma; 
// Made for Lenntech Water- & Luchtbehandeling Holding B.V.
// www.lenntech.com       info@lenntech.com
// 18 september 2002
// Copyright Jasper Elgersma & Lenntech
//------------------------------------------------------------

var duits=17.8;
var frans=10.0;
var engels=14.3;
var millival=50;
var ppm=1;
var mmol=100;

var temp

var input=document.hardheid.input.value;
var extentie=document.hardheid.type.value;

if (extentie=="duits"){temp=input*duits}
if (extentie=="frans"){temp=input*frans}
if (extentie=="engels"){temp=input*engels}
if (extentie=="millival"){temp=input*millival}
if (extentie=="ppm"){temp=input*ppm}
if (extentie=="mmol"){temp=input*mmol}

document.hardheid.duits.value=(temp/duits).toPrecision(3);
document.hardheid.frans.value=(temp/frans).toPrecision(3);
document.hardheid.engels.value=(temp/engels).toPrecision(3);
document.hardheid.millival.value=(temp/millival).toPrecision(3);
document.hardheid.ppm.value=(temp/ppm).toPrecision(3);
document.hardheid.mmol.value=(temp/mmol).toPrecision(3);
}

//met entertoets laten berekenen!
document.onkeypress = keyhandler;
function keyhandler(e) 
{
	Key = (document.layers)?e.which:window.event.keyCode;
	if( Key == 13 || Key == 32 )
	{ //13 is ascii value for Enter key 32 is space
		berekenhardheid(); 
	}
}

// end hiding script from old browsers -->