Untitled

<!DOCTYPE HTML>

<html>

<head>
    <title> Test </title>
    <meta charset="utf-8">

<SCRIPT>
function Action(){
    if (document.box.checked) alert('1');
    else alert('0');
}

</SCRIPT>

</head>

<body>

<input type="checkbox" id="box" name="box">
<input type="button" name="knopka" onclick="alert(Action)" value="action!">

</body>

</html>