Evening all.

I have a problem with some undefined variables ina function.

Although there are comments in the code below, this is how it works.
  • When the user presses the button, a ranom number is generated
  • This numer is converted to a 1 or 0
  • this updates the running totals
  • the totals are displayed in the table

The problem is that although it loads properly, I can't get the variable to update the table - I just getundefined.

Here's the code:
Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Teabag calculator</title>
<script language="javascript" type="text/javascript">
i=0;
var total=80;
var single=0;
var dbl=80;
var i=0;
function maketea()
{
document.getElementById('tries').innerHTML=i.value;
var randomnumber=Math.floor(Math.random()*2);
if (randomnumber==0)
//low, ie single
/*if a single bag is pulled, the doubles are unaffected, the singles fall by one 
the total number falls by one, and the number of tries increases by one*/
	{
		single=single-1;
		total=dbl+single;
		i=i+1
		document.getElementById('tries').innerHTML=i.value;
		document.getElementById('doubles').innerHTML=dbl.value;
		document.getElementById('singles').innerHTML=single.value;
		document.getElementById('total').innerHTML=total.value;
		document.getElementById('doubles').style.color="black";
		document.getElementById('singles').style.color="red"
	}
else if(randomnumber==1)
//high, ie double
/*if a double is pulled, the doubles fall by one, the singles increase by one, 
thetotal number stays the same and the tries goes up*/
	{
		dbl=dbl-1;
		single=single+1;
		total=dbl+single;
		i=i+1;
		document.getElementById('tries').innerHTML=i.value;
		document.getElementById('doubles').innerHTML=dbl.value;
		document.getElementById('singles').innerHTML=single.value;
		document.getElementById('total').innerHTML=total.value;
		document.getElementById('singles').style.color="black";
		document.getElementById('doubles').style.color="red";
	}
};
</script>
<style type="text/css">
<!--
.style1 {font-size: large}
-->
</style>
</head>

<body>
This page simulates the "Dad problem", as illustrated on <a href="http://answers.yahoo.com/question/index;_ylt=AvyknayS8m5RMuoYpmoj_lPsy6IX;_ylv=3?qid=20090106022211AAr5W7Q">Yahoo! Answers</a>.
<hr />
<INPUT TYPE="button" NAME="myButton" VALUE="Make the tea!" onClick="maketea()">
<table width="125" border="0" cellspacing="0" cellpadding="0">
  <caption align="top">
  <span class="style1">In the box</span>
  </caption>
  
  <tr>
    <td>Number of cups made</td>
    <td>Doubles left</td>
    <td>Singles left</td>
    <td>Total in the box</td>
  </tr>
  <tr>
    <td id="tries">&nbsp;
    </td>
    <td id="doubles">80</td>
    <td id="singles">&nbsp;</td>
    <td id="total">80</td>
  </tr>
</table>

</body>
</html>
Can anyone help?