Servlets :: HTTP Status 404 Error In Basic Login Form

I'm trying to learn java by making a login page using java, servlet, javascript, html and mysql. I can login with username and password, I can get all the information from database in the edit page. However, when I edit and click on "Submit" in EditPage.jsp, it gives HTTP Status 404. Same screen appears when I click on "Sign Up" from first page (NewFile.jsp) and click on "Submit" button after filling up user information.

I am posting all my code here but probably important ones are:

EditPage.jsp, Edit.java, EditDetails.java, UpdateUser.java and for Sign Up SignUpPage.jsp and Registration.java.

Firstly here are my error message and ss from my project explorer:

Here is my code:

LoginServlet.java
package com.amzi.servlets;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;

[Code] ....