window.prompt stop working when adding function

Question

var user = window.prompt("Welcome to the Vacation Planner. Please enter yourname");
document.getElementById("greeting").innerHTML += ", " + user;
var enterDays = document.getElementById("enterDays");
/*
function.calculateDays(){
    var dayMessage = document.getElementById("dayMessage");
    if(enterDays <4){
        dayMessage.innerHTML = "Short trips are always worth it!";
        }
    else if(enterDays<7){
        dayMessage.innerHTML = "Cool, you'll be there for a week"
        }
    else{
        dayMessage.innerHTML = "You'll have plenty of time to relax and have fun!"
        }
}*/
enterDays.onclick = calculateDays;

When I enter this code, the window.prompt work correctly. But when I uncomment the function.calculateDays, the window.prompt stop working. Can anybody explain why is it happening and how to solve it? Thanks a lot!!!

Answer 1

function.calculateDays是无效的语法，并且会引发语法错误，该错误将阻止将来的代码调用，要对其进行修复，请用function calculateDays替换它。