JS对多值表单组件[复选框]，下拉框，单选框的数据回显

<script type="text/javascript">         <!--获取先前设置好的兴趣爱好值，并添加到修改页面 -->           var arr = document.getElementsByName("hobby");           <%String[] hobbys = stu.getHobby();                if(hobbys!=null){                	 for(String s:hobbys){%>                     	 for(var i=0;i<arr.length;i++){                	      		if('<%=s%>'==arr[i].value){      		  		        	         	    arr[i].checked = 'checked';  		        				}                         }  											                	                    <%                    }                 }             %>            var sexs = document.getElementsByName("sex");             <%	String sex = stu.getSex();%>             for(var i=0;i<sexs.length;i++){                	      	if('<%=sex%>'==sexs[i].value){      		  		        	             sexs[i].checked = 'checked';  		        		  }                     }             var politics = document.getElementsByTagName("option");                     <%String pt=stu.getPolitics();%>             for(var i=0;i<politics.length;i++){                	      	if('<%=pt%>'==politics[i].value){      		  		        	             politics[i].selected = 'selected';  		        		  }                     }              </script>