HTML - Age Calculation

Could someone please tell me how to do the simplest of calculations on a webpage?

Take in a few values - three or four only.

Do some multiplying on them.

Output the results to the page.

I know it can't be done in html.

I feel it is probably a javascript candidate.

But how, exactly, to put the two together and do it?

Sorry to be so dumb. We all gotta start somewhere.

Hello,

I worked very hard on creating this calculation form. Now I am trying to input some radio buttons (MALE/FEMALE). The formulas are different:

MALE
function formula(x,y){
return ((x+y-1)/12);

FEMALE
function formula(x,y){
return ((x+y+1)/12);

Can someone please help me?? I gave up trying after 7 h. I can`t do this anymore, it seems impossible to me.

<script type="text/javascript">
function $(el)
{
return document.getElementById(el);
}

function formula(x,y){
return ((x+y-1)/12);
}

function check()
{
var x=parseInt($('x').value);
var y=parseInt($('y').value);
if($('x').value.length>0 && $('y').value.length>0)
{
$('result').value=formula(x, y);
}
}
</script>


<table>
<tr><td width="50%"><font face="arial" size="2" color="#FFCCFF"><b><input type="radio" name="male" value="male"checked>MALE</b></font></td>
<td width="50%"><font face="arial" size="2" color="#FFCCFF"><b><input type="radio" name="female" value="female">FEMALE</b></font></td></tr>
<tr><td>
x:</td><td><input type="text" id="x" onclick="this.select()"/></td></tr>
<tr>
<td>
y:</td><td><input type="text" id="y" onclick="this.select()"/></td></tr>
<tr><td>
Rezult
<input name="button" type="button" onclick="check()" value="calculate" /></td><td><input id="result" type="text" disabled style="width:100px; height:40px; text-align:center; vertical-align:middle"/></td>
<tr><td>&nbsp;</td>
<tr>
<td>&nbsp;</td>
</table>
</td>

THANK YOU!!!!!

Hey guys new here so thank you in advance for any help.

I am building my first site and I want to have a form on it where users of the page can submit info into a form and then be provided info about that info.

For example:
How many A's do you want to buy?
User inputs a number or selects from a drop down of numbers

How many B's do you want to buy?
User inputs a number or selects from a drop down of numbers


Then I want to the user to see instant feedback on the site that says "Your total is $x.xx"


Is this possible?
Thanks again

Hey guys!
I'm working on a web page for a loan redemption calculation. I want people to enter the loan amount, the interest rate, and the monthly redemption rate. The program should tell them then how many month it takes to pay back the entire loan and how much accumulated interest they have to pay. I tried it with this loop :
(interestRate , loan and redemption are defined before this loop)
Code:

        monthCount = 0
	begOfMonth = loan
	interest = 0
	valueWithoutInterest = 0
	endOfMonth = 1
	accInterest = 0
	
	for(i=1;endOfMonth>0;i++){
		interest = begOfMonth * interestRate / 1200
		accInterest = accInterest + interest
		valueWithoutInterest = begOfMonth + interest
		endOfMonth = valueWithoutInterest - redemption
		begOfMonth = endOfMonth
		monthCount = i
	}
	
	document.getElementById("resLoan").innerHTML = loan
	document.getElementById("resInterest").innerHTML = interestRate
	document.getElementById("resRedRate").innerHTML = redemption
	document.getElementById("resIntPayed").innerHTML = accInterest
	document.getElementById("resRuntime").innerHTML = monthCount

for some reason, this loop is infinite. When i modify the loop to calculate only 1 month, the numbers are correct. When i let it calculate 2 month, the accInterest explodes to a completely wrong value.
I checked it so many times and i just cant find any mistake...
I hope one of you guys can help me.

thanks in advance!

ps: sorry for the grammar