The following code example shows how to use the FromPoint method. This example creates a Point referencing the X and Y coordinates passed by a MouseEventArgs, and then uses the FromPoint method to determine if the point clicked is on the primary screen.
privatevoid Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
Point p = new Point(e.X, e.Y);
Screen s = Screen.FromPoint(p);
MessageBox.Show("You clicked the primary screen");
MessageBox.Show("This isn't the primary screen");