what's wrong with my variable, it's undefined

what's wrong with my variable, it's undefined

my variable todoHtmlLi is undefined, really can't get it why.. I had
declared it early before assign it to some html. I use console.log() to
check the priority value, it work just fine..
$(document).on('click', '#addTodoBtn', function (){
var todoDialog = {
state0: {
html: dialogContent,
buttons: {Cancel:-1 , Add:0},
focus: 1,
submit:function(e,v,m,f){
e.preventDefault();
var todoHtmlLi;
var todoNameVal;
var todoNoteVal;
//Task Name
todoNameVal = $("#todoName").val();
todoNameVal.trim();
//Note
todoNoteVal = $("#todoNote").val();
todoNoteVal.trim();
//Priority
priority = $("#priority").val();
if($(priority) === 1){
todoHtmlLi = "<li style='background:red'><a href='#'>"
+ todoNameVal + "<input type='checkbox'></a></li>"
}else if($(priority) === 2){
todoHtmlLi = "<li style='background:green'><a
href='#'>" + todoNameVal + "<input
type='checkbox'></a></li>"
}else if($(priority) === 3){
todoHtmlLi = "<li style='background:blue'><a
href='#'>" + todoNameVal + "<input
type='checkbox'></a></li>"
}
if(v == 0){
if(todoNameVal !== ""){
$("div#tab").find('#todoUl').prepend(todoHtmlLi);
$.prompt.close();
}else{
$("#todoName").focus();
}
}else{
$.prompt.close();
}
}
}
}
$.prompt(todoDialog);
});
if(v == 0){ mean the 'yes' button is clicked