When I use this code the console.log and the value in the field disappear right away.
window.onload = bereken;
function bereken(){
var knop = document.getElementById('berekenKnop').onclick = function (){
var aantalKm = document.getElementById('bereken');
console.log(aantalKm.value);
};
}
How can I prevent that from happening. Or what am I doing wrong?
The final goal will be to append the result of a calculation by the value of the field into another field.
edit:
<html>
<head>
<script src="bereken.js"></script>
</head>
<body>
<form id="berekenForm">
Bereken: <input type="text" name="bereken" id="bereken"/><br />
<input type="submit" value="Bereken" id="berekenKnop"/>
</form>
</body>
</html>
The submit button is doing its default task. i.e. submitting the form. Try handling that.