How to getrid of probelm occured in gridview

private void loadDynamicGrid()
{
DataTable table = new DataTable();
TextBox tx = new TextBox();
CheckBox ab = new CheckBox();
table.Columns.Add("Dynamic grid", typeof(string));
table.Columns.Add("Drug", typeof(Control));

// Here we add five DataRows.
table.Rows.Add("student first name:", tx);
table.Rows.Add("student last name:", tx);
table.Rows.Add("going to school"+ ab,ab);
table.Rows.Add("school name", tx);
table.Rows.Add("Grade:");


foreach (DataColumn col in table.Columns)
{
//Declare the bound field and allocate memory for the bound field.
BoundField bfield = new BoundField();


//Initalize the DataField value.
bfield.DataField = col.ColumnName;


//Initialize the HeaderText field value.
bfield.HeaderText = col.ColumnName;

//Add the newly created bound field to the GridView.
GrdDynamic.Columns.Add(bfield);
//TextBox t = new TextBox();


}

this.GrdDynamic.DataSource = table;

//Bind the datatable with the GridView.
GrdDynamic.DataBind();
}
protected void Button1_Click1(object sender, EventArgs e)
{
GrdDynamic.Visible = true;
int grid = Convert.ToInt32(TextBox1.Text);

for (int i = 0; i < grid; i++)
{

loadDynamicGrid();

}
Panel1.Controls.Add(GrdDynamic);


}