Select At list on check box in checkbox list in asp.net using jquery

Can anyone suggest what mistake i did in following scripts so it is not able to validate the checkbox list

<script type ="text/javascript" > 

            $.validator.addMethod('SelectAtlistOne', function (value, element) {
            if (debug) {
                $.jGrowl("Adding Validation");
            }
            var chkGroup = $("input[id^=<%=ckSkills.UniqueID %>]");
            if (chkGroup.length > 0) {
                for (var i = 0; i < chkGroup.length; i++) {
                    if ($(chkGroup[i]).attr('checked')) {
                        if (debug) {
                            // alert(i + $(chkGroup[i]).val());
                            $.jGrowl("Running loop " + i + " = " + $(chkGroup[i]).val());
                        }
                        return true;
                    }
                }
                return false;
            }
            return false;
        }, 'Please select at least one option');
        $("#form1").validate({

            rules: {                    
                <%=ckSkills.UniqueID %>: {         
                    SelectAtlistOne:true                    
                }

            }
            }

        });
    });   
</script>

Checkbox list is like

<asp:CheckBoxList ID="ckSkills" runat="server" RepeatDirection="Horizontal">
            </asp:CheckBoxList>

This list is is binding in run time. Please suggest me what i need to modify to make this code executable. I don't want to add separate function for checkbox list and validate it.