想請教各位大大
我有一個表格，checkbox,value(預設0),item
我希望使用者checkbox按下去後，value自動重0變1
但一值變不過去....
想請教各位到底是錯在哪?

<div class="container">
  <table ><tbody id="myTable">
   <%
          String sql = "select * from send"; 
            pstmt = conn.prepareStatement(sql);  
             ResultSet rs = pstmt.executeQuery(); 
             pstmt.setQueryTimeout(60);
	         while(rs.next()){ 
                String name = rs.getString("name");
                  String c_id = rs.getString("c_id"); 
      out.print("<tr><td>"+"<input type='checkbox' name='a' value="+c_id+" onclick='testfun( this ,"+c_id+")'>"+"</td>" + "<td><input type='text' id='"+c_id+"' name='count' value=0 SIZE=5></td><td>"+name+"</td></tr> ");
     }
	                rs.close(); 
 %>
    </tbody>
  </table>
  </form>
</div>
<script type="text/javascript">
function testfun(element, c_id) {
  var x = document.getElementById(c_id);
 window.alert(c_id);
  if (element.checked) {
    x.value =1;
  } else {
    x.value = 0;
  }
}
</script>
   

謝謝大家