Javascript auto calculating with (+) and (-)
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Josh
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Published on 2011-01-01T07:43:15Z
Indexed on
2011/01/01
7:54 UTC
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Filed under:
JavaScript
|calculation
I need some help finding the error in my javascript calculation.
I need to calculate the sum of my input boxes automatically and have my user be able to edit the calculation using + or - buttons.
The code I have already does the calculation automatically if you manually enter the numbers, but pressing the + or - does not change the calculation.
Here is the code:
<html>
<head>
<script language="javascript">
function Calc(className){
var elements = document.getElementsByClassName(className);
var total = 0;
for(var i = 0; i < elements.length; ++i){
total += parseInt(elements[i].value);
}
document.form0.total.value = total;
}
function addone(field) {
field.value = Number(field.value) + 1;
}
function subtractone(field) {
field.value = Number(field.value) - 1;
}
</script>
</head>
<body>
<form name="form0" id="form0">
1: <input type="text" name="box1" id="box1" class="add" value="0" onKeyUp="Calc('add')" onChange="updatesum()" onClick="this.focus();this.select();" />
<input type="button" value=" + " onclick="addone(box1);">
<input type="button" value=" - " onclick="subtractone(box1);">
<br />
2: <input type="text" name="box2" id="box2" class="add" value="0" onKeyUp="Calc('add')" onClick="this.focus();this.select();" />
<input type="button" value=" + " onclick="addone(box2);">
<input type="button" value=" - " onclick="subtractone(box2);">
<br />
3: <input type="text" name="box3" id="box3" class="add" value="0" onKeyUp="Calc('add')" onClick="this.focus();this.select();" />
<input type="button" value=" + " onclick="addone(box3);">
<input type="button" value=" - " onclick="subtractone(box3);">
<br />
<br />
Total: <input readonly style="border:0px; font-size:14; color:red;" id="total" name="total">
</form>
</body></html>
Im sure the issue must be small, I just cant put my finger on it.
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