<html>
<head>
<script>
function displayResult()
{
var x=document.getElementById("bike").value;
alert(x);
}
</script>
</head>
<body>
<form>
<input type="checkbox" id="bike" value="Bike"> I have a bike<br>
</form>
<button type="button" onclick="displayResult()">Display value</button>
</body>
</html>