webBrowser控件打开www.baidu.com,自动搜索里面是否有 网页 这两个字

//载入窗体的时候打开网页        private void Form1_Load(object sender, EventArgs e)        {            webBrowser1.Navigate("www.baidu.com");        }//判断是否含有textbox1中输入的关键字        private void button1_Click(object sender, EventArgs e)        {            if (textBox1.Text.Length == 0)            {                MessageBox.Show("输入需要查找的内容!");                return;            }            String s = webBrowser1.Document.Body.InnerHtml;            Boolean i = s.Contains(textBox1.Text);            if (i)                MessageBox.Show("网页中有关键字：" + textBox1.Text, "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);            else                MessageBox.Show("无法查找关键字：" + textBox1.Text, "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);        }