I'am a newbie here trying to set a value of a hidden field on button click fetching value from a radio button. For some reason I'am able to alert the value but while assigning, it always gives me null.

Please help.

Thanks in advance.

<script type=text/javascript>

function deleteCheck(){

    var values = document.getElementById(deleteVisitID).checked;



        if (values) {

            var hiddenInput = document.getElementById('deleteIDValue');

            *hiddenInput.value=document.getElementById(deleteVisitID).value;* <---- throws error



            window.open(DeleteAppointmentSelected.jsp,'_self',false);

        }else{

            alert('Please Enter a ID before submitting');           

        }

}



</script>

on the form

<table border=1>

    <tr><th>visit_id</th><th>visit_date</th><th>visit_time</th><th>physician_id</th><th>Delete Visit</th></tr>

    <%

    while(visitsForPatient.next()){

        %><tr>

            <td>

                <% visit_id=visitsForPatient.getString(1);%>

                <%=visit_id %>

            </td>

            <td>

                <%visit_date=visitsForPatient.getString(2);%>

                <%=visit_date %>

            </td>

            <td>

                <%visit_time=visitsForPatient.getString(3);%>

                <%=visit_time %>

            </td>

            <td>

                <%physician_id=visitsForPatient.getString(4);%>

                <%=physician_id %>

            </td>

            <td>

<input type=radio name=deleteVisitID id=deleteVisitID value=<%=visit_id %>/>

            </td>





        </tr>



        <%



    }

    %></table><input type=hidden name=deleteIDValue/>