Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Undefined checkbox

Posted on 2004-09-05
3
1,279 Views
Last Modified: 2012-05-05
The program will return an undefined string when there is only one checkbox. Why and how to fix it?

thanks.
0
Comment
Question by:hawkly
3 Comments
 
LVL 14

Accepted Solution

by:
ziffgone earned 25 total points
ID: 11986920
Pretty vague question, but try this out:

<script type="text/javascript">
var chkbox= document.form_name.elements['checkbox_name'];
if(chkbox.checked == true){
       var val = document.formname.elements['checkbox_name'].value;
}
else{
       var val = "";
}
alert(val);
</script>

Hope that helps.

Regards...
0
 
LVL 7

Expert Comment

by:Xxavier
ID: 11987020
"The program will return an undefined string when there is only one checkbox, Why and how to fix it?"

Probably because when there is only one checkbox the string variable is not assigned a value. To fix it make sure the variable is assigned a value when there is only one checkbox
0
 
LVL 8

Assisted Solution

by:RozanaZ
RozanaZ earned 25 total points
ID: 11987413
<HTML>
<HEAD>
<TITLE></TITLE>

<script>
function getValue()
{
      checkObj = document.getElementById("ch1");
      alert("Selected: " + checkObj.checked + " value: " + checkObj.value);
}
</script>
</HEAD>
<BODY>
<form>
<input type="checkbox" name="ch1" id="ch1" value="CheckBox 1">CheckBox 1<br>
<input type="button" value="Get Value" onClick="getValue()">
</form>
</BODY>
</HTML>
0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

This article shows how to create and access 2-dimensional arrays in JavaScript.  It includes a tutorial in case you are just trying to "get your head wrapped around" the concept and we'll also look at some useful tips for more advanced programmers. …
Today, the web development industry is booming, and many people consider it to be their vocation. The question you may be asking yourself is – how do I become a web developer?
The viewer will learn the basics of jQuery, including how to invoke it on a web page. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery.: (CODE)
The viewer will learn the basics of jQuery including how to code hide show and toggles. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery…

837 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question