调试易

我现在想datagridview中添加一行的代码如下：
private void Form1_Load(object sender, EventArgs e)
        {            thisAdapter =  new SqlDataAdapter("select * from chaxun where Gname='zhengfen'", myconnection);
            
            thisAdapter.Fill(thisDataset, "chaxun");
            dataGridView1.DataSource = thisDataset.Tables[0].DefaultView;
            if (thisDataset.Tables["chaxun"].Rows.Count == 0)
            {
                bupdate.Enabled = false;;
                bdelete.Enabled = false;
            }
            BindingSource bind = new BindingSource();
            bind.DataSource = thisDataset.Tables["chaxun"];
            bindingNavigator1.BindingSource = bind;
        }               private void insertbutton1_Click(object sender, EventArgs e)
        {
            string insCmd = "insert into chaxun(Gname,shijian)values(@Gname,@shijian)";
            thisAdapter.InsertCommand = new SqlCommand(insCmd, myconnection);
           SqlParameter parameter = new SqlParameter("@Gname", SqlDbType.Char, 20);
            thisAdapter.InsertCommand.Parameters.Add(parameter);
            parameter.SourceColumn = "Gname";
            parameter.SourceVersion = DataRowVersion.Current;                        SqlParameter parametershijian = new SqlParameter("@shijian", SqlDbType.DateTime);
            thisAdapter.InsertCommand.Parameters.Add(parametershijian);
            parametershijian.SourceColumn = "shijian";
            parametershijian.SourceVersion = DataRowVersion.Current;
            if (thisDataset.HasChanges())
            {
                try
                {
                    thisAdapter.Update(thisDataset, "chaxun");
                    MessageBox.Show("插入!");
                    bupdate.Enabled = true;
                    bdelete.Enabled = true;
                    
                }
                catch(SqlException ex)
                {MessageBox.Show("ex.Message");}
            }
            else 
                MessageBox.Show("提供详细信息添加！");
            //thisAdapter.Update(thisDataset, "chaxun");
           
                    }
希望使Gname列的值等文本框textbox输入的值，怎么修改这段程序呀，急用，谢谢各位大虾了！