<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Unbenanntes Dokument</title>
<script type="text/javascript">
function rechnen(wert1,wert2) {
var ergebnis = parseInt(wert2)-parseInt(wert1);
document.form.zeitraum.value=ergebnis;
}
</script>
</head>
<body>
<form id="form" name="form" method="post" action="">
<input type="text" name="anfang" id="anfang" onkeyup="rechnen(this.form.anfang.value,this.form.ende.value);" />
<input type="text" name="ende" id="ende" onkeyup="rechnen(this.form.anfang.value,this.form.ende.value);" />
::
<input type="text" name="zeitraum" id="zeitraum" />
</form>
</body>
</html>