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@mchayapol
Last active September 8, 2015 04:06
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Cash Register Skeleton
<!DOCTYPE html>
<html>
<head>
<title>Cash Register</title>
<script>
function calculateChange() {
var purchase = document.getElementById('purchase');
var cash = document.getElementById('cash');
var change = document.getElementById('change');
var result = Number(cash.value) - Number(purchase.value);
console.log(result);
change.value = result;
}
function clearForm() {
document.getElementById('purchase').value = '';
document.getElementById('cash').value = '';
document.getElementById('change').value = '';
}
function isNumeric(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}
function validateNumber(inputObj) {
if (!isNumeric(inputObj.value)) {
alert('Invalid input');
inputObj.value = '';
}
}
</script>
</head>
<body>
<table>
<tr>
<td>Purchase</td>
<td><input type="text" onblur="validateNumber(this)" id="purchase" /></td>
</tr>
<tr>
<td>Cash</td>
<td><input type="text" id="cash" /></td>
</tr>
<tr>
<td>Change</td>
<td><input type="text" id="change" /></td>
</tr>
<tr>
<td colspan="2">
<button onclick="calculateChange()">Calculate</button>
<button onclick="clearForm()">Clear</button>
</td>
</tr>
</table>
</body>
</html>
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