Visual Studio OleDB Exception unhandled || I am writing a code to validate my form from access database in Visual Studio.

Code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;


namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private OleDbConnection connection = new OleDbConnection();
        public Form1()
        {

          InitializeComponent();    
         connection.ConnectionString=@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\bin\Debug\Login.accdb";

/* I think this connection string is weird. It is giving invalid path name when I run the code */ }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void label2_Click(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {
            connection.Open();
            if(String.IsNullOrWhiteSpace(textBox1.Text))
            {
                MessageBox.Show("The username cannot be blank! Please Enter again","Invalid User Name",MessageBoxButtons.OKCancel,MessageBoxIcon.Warning);
                textBox1.Select();
            }

            if (String.IsNullOrWhiteSpace(textBox2.Text))
            {
                MessageBox.Show("The password cannot be blank! Please Enter again", "Invalid Password", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning);
                textBox2.Select();
            }
            else if (textBox2.TextLength < 8)
            {
                MessageBox.Show("The password cannot be less than 8 characters. Please Enter again", "Invalid Password", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning);
                textBox2.Select();
            }

            else
            {
            DialogResult abc = MessageBox.Show("Hello! Login Successful", "Welcome box", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning);
            if (abc == DialogResult.Cancel)
            {
                this.Close();

            }
            else
            {
                Form3 frm = new Form3(textBox1.Text);
                frm.Show();
            }
            }
            OleDbCommand command = new OleDbCommand();
            command.Connection = connection;
            command.CommandText = "select * from LoginData where Username='" + textBox1.Text + "'and Password='" + textBox2.Text + "'";
            OleDbDataReader reader = command.ExecuteReader();
            int count = 0;
            while (reader.Read())
            {
                count = count + 1;
            }
            if (count == 1)
            {
                MessageBox.Show("Login Successfull!");
            }
            else
                MessageBox.Show("Invalid username and password");
            connection.Close();
        }


        private void button1_Click(object sender, EventArgs e)
        {
            ForgotPwd frm = new ForgotPwd();
            frm.Show();
        }

        private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            SignUp frm = new SignUp();
            frm.Show();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            try
            {
                connection.Open(); // the exception is unhandled here
                connection.Close();
            }
            catch (Exception ex)
            {
            }

        }

    }
}

/* the code basically validates data entered from the database. The database is stored in the debug folder of the project of visual studio*/