Deserve
Member
Posts : 7
Join date : 2011-05-11
 |  Subject: Object Error... Why???? Tue Jun 21, 2011 6:56 pm | |
| When I run this program is says I have an object error (not found?) in line 2, I went over the program which I copied from a book over and over and not finding anything wrong... Help!!! thanks HTML code here: - Code:
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<!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>Making Sums</title> <script type="text/javascript" src="jsb-08-01.js"></script> <script type="text/javascript" src="jsb-global.js"></script> </head> <body> <h1>Making Sums</h1> <form action="addit.php"> <p><input type="text" id="inputA" name="inputA" value="0" /></p> <p><input type="text" id="inputB" name="inputB" value="0" /></p> <p><input type="button" id="add" name="add" value="Add" /></p> <p><input type="text" id="output" name="output" /></p> </form> </body> </html> Javascript code here: - Code:
-
// initialize when the page has loaded
addEvent(window, 'load', initialize); // Here's where it says I have an error
function initialize()
{
// do this only if the browser can handle DOM methods
if(document.getElementById)
{
// point to critical elements
var oInputA = document.getElementById('inputA');
var oInputB = document.getElementById('inputB');
var oButton = document.getElementById('add');
var oOutput = document.getElementById('output');
// if they all exist...
if(oInputA && oInputB && oButton && oOutput)
{
//apply behaviors
addEvent(oButton, 'click', addIt);
}
}
}
// add two input numbers & display results
function addIt()
{
var value1 = document.getElementById("inputA").value;
var value2 = document.getElementById("inputB").value;
document.getElementById("output").value = value1 + value2;
}
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Impossible
Member
Posts : 2
Join date : 2011-05-11
| | Subject: Re: Object Error... Why???? Tue Jun 21, 2011 6:57 pm | |
| I don't see where you define addEvent. |
|
Deserve
Member
Posts : 7
Join date : 2011-05-11
| | Subject: Re: Object Error... Why???? Tue Jun 21, 2011 6:58 pm | |
| Here's the add event function that was missing: - Code:
-
/*
jsb-global.js
This file contains commonly-used functions for scripts accompanying
The JavaScript Bible 7th Edition (Wiley, 2009) by Danny Goodman with Paul Novitski et al.
*/
// add an event to an element
function addEvent(elem, evtType, func)
{
if (elem && typeof(elem) == "object")
{
// first try the W3C DOM method
if (elem.addEventListener)
{
elem.addEventListener(evtType, func, false);
}
// otherwise use the 'traditional' technique
else
{
elem["on" + evtType] = func;
}
}
}
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Skilletrockz
Super Moderator
Posts : 45
Join date : 2011-05-11
| | Subject: Re: Object Error... Why???? Tue Jun 21, 2011 6:58 pm | |
| jsb-08-01.js is calling addEvent, which is in jsb-global.js, which loads later. Reverse their inclusion tags. |
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Deserve
Member
Posts : 7
Join date : 2011-05-11
| | Subject: Re: Object Error... Why???? Tue Jun 21, 2011 6:59 pm | |
| skilletrockz... Makes sense... I wasn't thinking about that. Forgive a newbie... It definatley will be something I will think about next time though, thanks to you. |
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| | Subject: Re: Object Error... Why???? | |
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