How to open an application, file Using Shell execute in .net

We can execute any application(any files,notepad,calculator and etc) using C#.net by
System.Diagnostics.Process.Start.

Coding :

private void bt_ShellExecute_Click(object sender, EventArgs e)
{
string strpath = "C:\\sample.xls";

System.Diagnostics.Process.Start(strpath);
}