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I have a group of checkboxes.
I need a validation such that atleast one checkbox must be checked or else I should get a message to select at least one checkbox.

Can any one help me out?
Updated 12-Sep-10 22:48pm
Dalek Dave 13-Sep-10 3:48am    
Edited for Grammar.

You can use java script to validate it. Here is an example for three check boxes .

<script type="text/javascript" language="JavaScript">
function checkCheckBoxes(theForm) {
    if (
    theForm.CHECKBOX_1.checked == false &&
    theForm.CHECKBOX_2.checked == false &&
    theForm.CHECKBOX_3.checked == false)
        alert ('Select any check box!');
        return false;
    } else {
        return true;

if you have more check boxes , use 'for' loop to iterate to find whether any one is checked or not. For this the check box names must be like a indexed one as in example

if your need is not satisfied please read this
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srujanac# 13-Sep-10 6:24am    
should i make any changes in my .aspx.cs page i.e in my code.Like to call the javascript function which i have written.
Baji Jabbar 13-Sep-10 13:14pm    
You have to add the attribute.Add property to call the javascript. On pageload add Button1.Attributes.Add("OnClick","return checkCheckBoxes(this)"
srujanac# 14-Sep-10 6:39am    
ya i got it thanks
You can use

var elements = document.getElementsByName('groupname');

for(var i=0; i< elements.length; i++)
 //check if any elements[i] is checked

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srujanac# 13-Sep-10 6:35am    
what should my group name be here I have taken checkboxes individually.And there is no property for checkboxes like 'name' in order to give a paticular groupname
For a Simple,
Use RequiredFieldValidator to CheckBoxList
it will throw msg if No checkbox is selected.
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srujanac# 14-Sep-10 5:22am    
I tried but its showing me a mesg that we cannot use required field validator to checkboxlist
Hiren solanki 14-Sep-10 5:35am    
if you are using C#, then validate it at server side like
if (CheckBoxList1.SelectedIndex > 0) (it mean one of checkbox is checked )
Hiren solanki 14-Sep-10 5:37am    
sorry i am not able to edit my comment use CheckBoxList1.SelectedIndex >= 0 to ensure that atlease one checkbox is checked.
Check this thread[^]

And avoid multiple post.:mad:
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