<html>
<head>
<script>
window.dhx_globalImgPath = "codebase/imgs/";
</script>
<script  src="codebase/dhtmlxcommon.js"></script>
<script  src="codebase/dhtmlxslider.js"></script>
<script  src="codebase/ext/dhtmlxslider_start.js"></script>
<link rel="STYLESHEET" type="text/css" href="codebase/dhtmlxslider.css">
    <script language="javascript">
        function Berekenen()
        {
            var badagen = document.getElementById('badagen');
            var select1 = document.getElementById('select1');
            badagen.value = select1.value*0.04; // Wanneer je 4 cent wil moet je het waarschijnlijk veranderen naar 0.04!
        }
    </script> 
</head>
<body>
<?php
if(isset($_POST['submit'])){
echo '<h2>Je word nu voor '.$_POST['badagen'].' dagen betaald account.</h2>';
}
?>
<font face="arial">Koop credits:</font><br />
<table width="600">
<tr>
<th><b><font face="arial">Aantal</font></th>
<th><b><font face="arial">Schuifbalk</font></b></th>
<th><b><font face="arial">Prijs</font></b></th>
<th><b><font face="arial">Bevestig</font></b></th>
</tr>
<tr>
<form method="post">
<td><input onSelect="Berekenen()" type="text" id="select1" size="2" name="select1"></td>
<td>
<script>
var slider3 = new dhtmlxSlider(null, 150, "arrow", null, 14, 250);
slider3.setStep(2);
slider3.linkTo('select1');
slider3.init();
slider3.onFocus="Berekenen()";
</script>
</td>
<td><input type="text" id="badagen" size="2" name="badagen" disabled="disabled" /></td>
<td><input onclick="Berekenen()" type="button" value="Reken uit!" /><input type="submit" name="submit" value="Koop"></td>
</form>
</tr>
</table>
</body>
</html>

<html> 
<head> 
<script> 
window.dhx_globalImgPath = "codebase/imgs/"; 
</script> 
<script  src="codebase/dhtmlxcommon.js"></script> 
<script  src="codebase/dhtmlxslider.js"></script> 
<script  src="codebase/ext/dhtmlxslider_start.js"></script> 
<link rel="STYLESHEET" type="text/css" href="codebase/dhtmlxslider.css"> 
    <script language="javascript"> 
function bereken(){
aantal = document.getElementsByName('select1')[0].value;
// value ophalen aantal input box
ps = '0.04';
// prijs per stuk
prijs = ps*aantal;
// prijs uitrekeken.


document.getElementsByName('badagen')[0].value = prijs;
// prijs in het veld zetten
}
    </script>  
</head> 
<body> 
<?php 
if(isset($_POST['submit'])){ 
echo '<h2>Je word nu voor '.$_POST['badagen'].' dagen betaald account.</h2>'; 
} 
?> 
<font face="arial">Koop credits:</font> 
<table width="600"> 
<tr> 
<th><b><font face="arial">Aantal</font></th> 
<th><b><font face="arial">Schuifbalk</font></b></th> 
<th><b><font face="arial">Prijs</font></b></th> 
<th><b><font face="arial">Bevestig</font></b></th> 
</tr> 
<tr> 
<form method="post"> 
<td><input onchange="bereken()" type="text" id="select1" size="2" name="select1"></td> 
<td> 
<script> 
var slider3 = new dhtmlxSlider(null, 150, "arrow", null, 14, 250); 
slider3.setStep(2); 
slider3.linkTo('select1'); 
slider3.init(); 
slider3.onFocus="Berekenen()"; 
</script> 
</td> 
<td><input type="text" id="badagen" size="2" name="badagen" disabled="disabled" /></td> 
<td><input onclick="bereken()" type="button" value="Reken uit!" /><input type="submit" name="submit" value="Koop"></td> 
</form> 
</tr> 
</table> 
</body> 
</html>