请高手看看什么毛病！！！
小弟感知不禁！！！！
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace jiadang
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
long oper1, oper2, result;
if ((textBox1.Text == "") || (textBox2.Text == ""))
{
MessageBox.Show(this, "操作数不能为空", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
try
{
oper1 = Convert.ToInt64(textBox1.Text);
oper2 = Convert.ToInt64(textBox2.Text);
result = oper1 + oper2;
textBox3.Text = Convert.ToString(result);
}
catch (Exception e1)
{
MessageBox.Show(this, e1.Message, "警告信息", MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
}}

private void buttonExit_Click(object sender, System.EventArgs e)
{
this.Close();
}
}
}