How to get the CheckBoxlist Value using Javascript

A CheckBoxList renders as an HTML Table tag and does not have checked property. The child controls are CheckBoxes and do have the checked property.

There is no client-side "value" property in a CheckBoxList.

That is a server-side only property. You can only get the Text property of the ListItem (Item 1, Item 2, etc in this example).

Example:

<form id="form1" runat="server">
 <asp:CheckBoxList id="CheckBoxList1" runat="server">
  <asp:listitem Value="1">Item 1</asp:listitem>
  <asp:listitem Value="2">Item 2</asp:listitem>
  <asp:listitem Value="3">Item 3</asp:listitem>
 </asp:CheckBoxList>
 <input type="button" onclick="readCheckBoxList();" value="Read CheckBoxList" />
</form>

<script type="text/javascript">
<!--
function getCheckBoxListItemsChecked(elementId)
{
 var elementRef = document.getElementById(elementId);
 var checkBoxArray = elementRef.getElementsByTagName('input');
 var checkedValues = '';

 for (var i=0; i<checkBoxArray.length; i++)
 {
  var checkBoxRef = checkBoxArray[i];

  if ( checkBoxRef.checked == true )
  {
////////////
// AFAIK, you cannot get the value property of a ListItem in a CheckBoxList.
// You can only get the Text property, which will be in an HTML label element.
////////////

   var labelArray = checkBoxRef.parentNode.getElementsByTagName('label');

   if ( labelArray.length > 0 )
   {
    if ( checkedValues.length > 0 )
     checkedValues += ', ';

    checkedValues += labelArray[0].innerHTML;
   }
  }
 }

 return checkedValues;
}
function readCheckBoxList()
{
 var checkedItems = getCheckBoxListItemsChecked('<%= CheckBoxList1.ClientID %>');
 alert('Items checked: ' + checkedItems);
}
// -->
</script>