Originally Posted 2001

Only submit if at least one checkbox is checked

A Question I got:

I would like to show an alert if no check box was checked in a field. The idea is that at least one check box should be checked. I have an onSubmit for the form and a JS function that suppose to check it but it does not work.

HTML Source Code

    <form action="/" onsubmit="return checkCheckBoxes(this);">
        <p><label><input type="CHECKBOX" name="CHECKBOX_1" value="This..."> This...</label></p>
        <p><label><input type="CHECKBOX" name="CHECKBOX_2" value="That..."> That...</label></p>
        <p><label><input type="CHECKBOX" name="CHECKBOX_3" value="...and The Other"> ...and The Other</label></p>
        <p><input type="SUBMIT" value="Submit!"></p>
    </form>

Source Code

<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 ('You didn\'t choose any of the checkboxes!');
		return false;
	} else { 	
		return true;
	}
}
//-->
</script>