Drop down menu to call functions?

[cirustus]

im trying to create a calculator that adds divides and multiplies either decimal or binary input. i have worked out the 2 functions to do this but i dont know how to call the functions using a pull down menu so when i click calculate it uses the appropriate function.

i have pasted the code down below any help would be great

<html>

<head>
<script type="text/javascript">
function dec(a,b,c)

{

	var a;
	var b;
	var c;
	var answer;
	
	a = parseInt(a, 10)
//	b = parseInt(b, 10)
	c = parseInt(c, 10)
	
	if (b=="+")
	{
		answer = a + c
		document.write(answer)
	}
	
	else if (b=="*")
	{
		answer = a * c
		document.write(answer)
	}
	
	else 
	{
		answer = a / c
		document.write(answer)
	}
	
}

</script>

<script type="text/javascript">
function bin(a,b,c)
{

	var a;
	var b;
	var c;
	var answer;
	
	a = parseInt(a, 2)
//	b = parseInt(b, 2)
	c = parseInt(c, 2)
	
	if (b=="+")
	{
		answer = a + c
		document.write(answer.toString(10))
	}
	
	else if (b=="*")
	{
		answer = a * c
		document.write(answer.toString(10))
	}
	
	else 
	{
		answer = a / c
		document.write(answer.toString(10))
	}
	
}
</script>


</head>

<body>


<form>
	<input type="text" name="a" size="2">
	<p>
	<input type="text" name="b" size="2">
	<select name="ab">
	<option value=""></option>
	<option value="dec">Decimal</option>
	<option value="bin">Binary</option>
	</select>
	</p>
	<p>
	<input type="text" name="c" size="2">
	</p>
	<p>
	<input type="button" value="Calculate" onclick="(a.value, b.value, c.value)">
	</p>
</form>

</body>

</html>

[acoder]

Rather than 2 functions, use one function and pass ab.value to it. Then use that to determine whether to use base 2 or base 10.

PS. using a, b, c in the global context is incorrect. Use document.getEle mentById() after giving the elements IDs or use document.forms["formName"].a, etc. where "formName" is the name of the form.