Newbie question

**Guerrilla** · 04-21-2005, 05:42 PM

Hi,

I am learning javascript. Its the first language i have attempted to learn and i am finding it a bit tricky.

I am at the interactivity with forms part in my course so i have attempted to write a script with 3 input boxes. The goal is to have the first box be a single value, the second is double the first and the third is the square of the first.

I have been trying to get it to work for absolutely ages but its just not happening. Its probably glaringly obvious so i have copied the code below to see if any kind developer can help me out.

Here goes :

Code:

<html>
<head>
<title>3 numbers</title>
<script type="text/javascript">

function calculate(form,whichop) {

		if(whichop == "single") {
		form.double.value = form.single.value * 2;
		form.square.value = form.single.value * form.single.value;
		
		} else(whichop == "double") {
		form.single.value = form.double.value / 2;
		form.square.value = form.single.value * form.single.value;
										
		} else(whichop == "square") {
		form.single.value = Math.sqrt(form.square.value);
		form.double.value = form.square.value * 2; 
		
		}}
	

</script>
</head>

<body>


<form>

number <input type="text" name="single" value="0" onChange="calculate(this.form,'single')"> 
double <input type="text" name="double" value="0" onChange="calculate(this.form,'double')"> 
square <input type="text" name="square" value="0" onChange="calculate(this.form,'square')">

</form>

</body>
</html>

I appreciate any help you can give me.

Thanks

**Phaedrus** · 04-21-2005, 06:46 PM

I think the "else" statements in the function should be "elseif" instead. You can only have one "else" for an if statement, and you've got two.

**Guerrilla** · 04-23-2005, 07:16 AM

i changed them to "else if" and it worked

Thanks for the help!