Js控制密保问题下拉框

Js控制密保问题下拉框
前段时间书写一个密保问题的验证，要求有三个密保问题并且上面问题选中后下面的选择框不再出现上面的值，看起来貌似很简单的可是真正做起来这个Js还是挺麻烦的现在把最终的发出来和大家分享下
var questions =new Array();
<c:forEach var="memberQuestion"items="${memberQuestions}">
questions.push({questionId:'${memberQuestion.questionId}', questionContext:'${memberQuestion.questionContext}'});
</c:forEach>
var question1 = document.getElementById("question1");
var question2 = document.getElementById("question2");
var question3 = document.getElementById("question3");
//初始化问题
function doInit(){
if(questions.length==0 || questions==null){
return;
}
for(var i=0;i<questions.length;i++){
var question = questions[i];
question1.options.add(new
Option(question.questionContext,question.questionId));
question2.options.add(new
Option(question.questionContext,question.questionId));
question3.options.add(new
Option(question.questionContext,question.questionId));
}
}
//下拉框改变事件
function doChange(){
var q1Id = question1.value;
var q2Id = question2.value;
var q3Id = question3.value;
var oneIndex = 0;
var twoIndex = 0;
var threeIndex = 0;
question2.options.length=0;
question1.options.length=0;
question3.options.length=0;
question1.options.add(new Option("--请选择密保问题--",0)); question2.options.add(new Option("--请选择密保问题--",0)); question3.options.add(new Option("--请选择密保问题--",0)); oneIndex = doResetSelectBox(q1Id,q2Id,q3Id,question1);
twoIndex = doResetSelectBox(q2Id,q1Id,q3Id,question2);
threeIndex = doResetSelectBox(q3Id,q1Id,q2Id,question3); question1.options.selectedIndex = oneIndex;
question2.options.selectedIndex = twoIndex;
question3.options.selectedIndex = threeIndex;
}
//加载当前下拉框并返回选择的索引值
function doResetSelectBox(currentId,otherId1,otherId2,selectBox){ var j=1;
var index = 0;
for(var i=0;i<questions.length;i++){
var question = questions[i];
var questId = question.questionId;
if(otherId1!="0"&&otherId1==questId){
continue;
}
if(otherId2!="0"&&otherId2==questId){
continue;
}
selectBox.options.add(new
Option(question.questionContext,question.questionId));
if(questId==currentId)
index = j;
j++;
}
return index;
}
doInit();。