C#

DataSet ds = new DataSet();<br />
            ds.ReadXml(@"D:\myappl\Student.xml", XmlReadMode.Auto);<br />
            dataGridView1.DataSource = ds.Tables[0];

private void dataGridView1_DoubleClick(object sender, EventArgs e)<br />
        {<br />
            MessageBox.Show("" + dataGridView1.CurrentCellAddress.Y);<br />
            MessageBox.Show(dataGridView1.Rows[dataGridView1.CurrentCellAddress.Y].Cells[0].Value.ToString());<br />
            Form2 f = new Form2(dataGridView1.Rows[dataGridView1.CurrentCellAddress.Y].Cells[0].Value.ToString());<br />
            f.val = dataGridView1.Rows[dataGridView1.CurrentCellAddress.Y].Cells[0].Value.ToString();<br />
            f.Show();<br />
        }

        public Form2(string  value1)<br />
        {<br />
            InitializeComponent();<br />
            //getst he value and the value is stored in the txt box<br />
            textBox1.Text = value1;<br />
            DataSet ds = new DataSet();<br />
            //populates the dataset<br />
            ds.ReadXml(@"D:\myappl\Student.xml", XmlReadMode.Auto);<br />
            //assigns the primary key field<br />
            ds.Tables[0].PrimaryKey = new DataColumn[] { ds.Tables[0].Columns[0] };<br />
            //finds and retrieves the row for the key<br />
            DataRow dr = ds.Tables[0].Rows.Find(textBox1.Text);<br />
            //populates the value you can extends also<br />
            textBox2.Text =Convert.ToString( dr[1]);<br />
<br />
        }<br />

<br />
       dr.delete();<br />
       ds.WriteXML(...)<br />

//Gets forms that represent the MDI child forms <br />
//that are parented to this form in an array <br />
Form[] charr= this.MdiChildren; <br />
     <br />
//For each child form set the window state to Maximized <br />
foreach (Form chform in charr) <br />
   chform.WindowState=FormWindowState.Maximized;