Display message box in ASP.Net

Create Simple class

public class MessageBox
{

private System.Web.UI.Page _Objp;
public MessageBox(System.Web.UI.Page page)
{
_Objp = page;
}
public void Show(string Message)
{
string script = "";
_Objp.Response.Write(script);
}

}

-- In Web Page .....

Create Object of Messagebox class

MessageBox _ObjMessageBox = new MessageBox();

_ObjMessageBox.Show("HI");