Changing Page Style for Printing

using System;
using System.Xml;
using System.Data;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

public class XmlDataMain : Page
{
	public DataGrid XmlDataGrid;
	
	// using ViewState for SortField property
	// For more information about using ViewState bags read the following reference
	// Reference:- http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspnet/html/asp11222001.asp
    string SortField {

        get {
            object o = ViewState["SortField"];
            if (o == null) {
                return String.Empty;
            }
            return (string)o;
        }

        set {
            if (value == SortField) {
                //if ascending change to descending or vice versa.
                SortAscending = !SortAscending;
            }
            ViewState["SortField"] = value;
        }
    }

    // using ViewState for SortAscending property
    bool SortAscending {

        get {
            object o = ViewState["SortAscending"];
            if (o == null) {
                return true;
            }
            return (bool)o;
        }

        set {
            ViewState["SortAscending"] = value;
        }
    }
    
	protected void Page_Load(Object src, EventArgs e)
	{
		if(!IsPostBack)
		{
			BindGrid();
		}
	}
	
	protected void BindGrid()
	{
		string dataUrl = "books.xml";
		string schemaUrl = "books.xsd";
		
		DataSet ds = new DataSet();
		ds.ReadXmlSchema(Server.MapPath(schemaUrl));
		ds.ReadXml(Server.MapPath(dataUrl));
		
		DataView dv = new DataView(ds.Tables[0]);
		DataTable dt = dv.Table;
		
		//Custom names for the columns
		dt.Columns[0].ColumnName = "Item Description";
		dt.Columns[1].ColumnName = "Item Id";
		dt.Columns[2].ColumnName = "Amount";
		
		//Sorting criteria
		dv.Sort = SortField;
        if (!SortAscending)
        {
            dv.Sort += " DESC";	//append "DESC" to the sort field name in order to sort descending
        }
        
		XmlDataGrid.DataSource = dv;
		XmlDataGrid.DataBind();
	}
	
	protected void SortGrid(Object src, DataGridSortCommandEventArgs e)
	{
		XmlDataGrid.CurrentPageIndex = 0;
   		SortField = e.SortExpression;	//get the requested sorting field name and set it to SortField
   		BindGrid();
	}
}