Validation Error without posting data in MVC - asp.net-mvc

Question

I am using same form for Inserting new records and updating existing records. But, issue is that validation on all controls are shown as soon as form is loaded i.e. it should display validation message summary once this does not match criteria. I want to avoid validation message summary before clicking on submit button.
Controller:
using CRUD_logudTycoon_Revision_3.Context;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
namespace CRUD_logudTycoon_Revision_3.Controllers
{
public class HomeController : Controller
{
// GET: Home
testEntities dbContext = new testEntities();
public ActionResult HomePage()
{
return View();
}
public ActionResult Student(tbl_Student obj)
{
if (obj != null)
{
return View(obj);
}
return View("Student");
}
public ActionResult Create()
{
return View();
}
[HttpPost]
public ActionResult AddStudent(tbl_Student stu)
{
if (ModelState.IsValid)
{
tbl_Student res = new tbl_Student();
res.ID = stu.ID;
res.Name = stu.Name;
res.Fname = stu.Fname;
res.Email = stu.Email;
res.Mobile = stu.Mobile;
res.Description = stu.Description;
if (stu.ID == 0)
{
dbContext.tbl_Student.Add(res);
dbContext.SaveChanges();
}
else
{
dbContext.Entry(res).State = System.Data.Entity.EntityState.Modified;
dbContext.SaveChanges();
}
}
ModelState.Clear();
//return View("Student");
return RedirectToAction("StudentList");
}
public ActionResult StudentList()
{
var result = dbContext.tbl_Student.ToList();
return View(result);
}
public ActionResult Delete(int ID)
{
var result = dbContext.tbl_Student.Where(x => x.ID == ID).First();
dbContext.tbl_Student.Remove(result);
dbContext.SaveChanges();
var newlist = dbContext.tbl_Student.ToList();
return View("StudentList", newlist);
}
}
}
Student Action (Insert/Edit):
#model CRUD_logudTycoon_Revision_3.Context.tbl_Student
#{
ViewBag.Title = "Student";
}
<style>
.error {
color: red;
}
</style>
<h2>Student Registration Page</h2>
#using (Html.BeginForm("AddStudent", "Home", FormMethod.Post))
{
#Html.AntiForgeryToken()
<div class="container">
<div class="form-group">
#Html.HiddenFor(x => x.ID)
#Html.Label("Student Name")
#Html.ValidationMessageFor(x => x.Name, "", new { #class = "error" })
#Html.TextBoxFor(x => x.Name, new { #class = "form-control" })
</div>
<div class="form-group">
#Html.Label("Father Name")
#Html.ValidationMessageFor(x => x.Fname, "", new { #class = "error" })
#Html.TextBoxFor(x => x.Fname, new { #class = "form-control" })
</div>
<div class="form-group">
#Html.Label("Email")
#Html.ValidationMessageFor(x => x.Email, "", new { #class = "error" })
#Html.TextBoxFor(x => x.Email, new { #class = "form-control" })
</div>
<div class="form-group">
#Html.Label("Mobile")
#Html.ValidationMessageFor(x => x.Mobile, "", new { #class = "error" })
#Html.TextBoxFor(x => x.Mobile, new { #class = "form-control" })
</div>
<div class="form-group">
#Html.Label("Description")
#Html.ValidationMessageFor(x => x.Description, "", new { #class = "error" })
#Html.TextBoxFor(x => x.Description, new { #class = "form-control" })
</div>
<div class="form-group">
#Html.TextBox("btn_Submit", "Submit", new { type = "Submit" })
#Html.TextBox("btn_Reset", "Reset", new { type = "Reset" })
</div>
</div>
}
DB Scripts:
CREATE TABLE [dbo].[tbl_Student]
(
[ID] [int] IDENTITY(1,1) NOT NULL,
[Name] [varchar](150) NULL,
[Fname] [varchar](150) NULL,
[Email] [varchar](150) NULL,
[Mobile] [varchar](150) NULL,
[Description] [varchar](350) NULL,
PRIMARY KEY CLUSTERED ([ID] ASC)
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON,
ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated from a template.
//
// Manual changes to this file may cause unexpected behavior in your application.
// Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
namespace CRUD_logudTycoon_Revision_3.Context
{
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
public partial class tbl_Student
{
public int ID { get; set; }
[Required(ErrorMessage ="Name is requried")]
public string Name { get; set; }
[Required(ErrorMessage = "Father Name is requried")]
public string Fname { get; set; }
[Required(ErrorMessage = "Email is requried")]
[EmailAddress]
public string Email { get; set; }
[Required(ErrorMessage = "Mobile is requried")]
[MinLength(10,ErrorMessage ="10 Digit Mobile No. is required")]
[MaxLength(10, ErrorMessage = "10 Digit Mobile No. is required")]
public string Mobile { get; set; }
[Required(ErrorMessage = "Description is requried")]
public string Description { get; set; }
}
}