Validate at least one checkbox has been checked

Form validation of checkboxes

[pops]

I have a form that has 18 checkboxes. I would like to verify that at least one of them has been checked. The checkboxes use the same form name. I know that by doing this, internally an array is setup with the 18 values. I also know that checkboxes actually are boolean true / false. My challenge, I don't know how to access the field that sets the true / false value. Can someone help me.

[Rambo Tribble]

Actually, forms don't support arrays, as such. It is usually server languages that interpret them as such. With JavaScript you will need to build the array by doing something like:

var ckbx_arr=document.getElementsByName('check_box_name');

You can then loop the array testing the "checked" property, something like:

var ckbx_arr_ln=ckbx_arr.length;
for(var i=0;i<ckbx_arr_ln;i++){
if(ckbx_arr[i].checked)return true;
}
return false;

[Rambo Tribble]

To respond to your sticky mail, my favorite reference is Danny Goodman's Dynamic HTML, on O'Reilly. Otherwise, the W3C's site is pretty good, for example: [w3.org...]

Generally it is preferred that you keep your follow-up qestions and comments in the thread, so others can gain from them, as well.