public function store(Request $request)

    {
        // this code for validation

        $this->validate(request(),[
            'Roll_Num'=>'required|unique:students,Roll_Num',
            'firstName'=>'required',
            'secondName'=>'required',
            'age'=>'required|min:1|max:40',
            'speciality'=>'required',
        ],
        [
           
            'age.required'=>"Age must be under 18 to 40"  
        ]
    );

        // this code for creating student record
        $student = new Student();
        $student->Roll_Num = $request->input('Roll_Num');
        $student->firstName = $request->input('firstName');
        $student->secondName = $request->input('secondName');
        $student->age = $request->input('age');
        $student->speciality = $request->input('speciality');
        $student->save();
        return redirect('/inde');
   
     }