The key press events include KeyDown, KeyUp, KeyPress. Event handling methods are defined in frmMain class and in InitializeComponent() method:

using System.Windows.Forms;
partial class frmMain
{
private void InitializeComponent()
{
this.Width = 1000;
this.Height = 600;
this.KeyPreview = true;
this.KeyPress += new KeyPressEventHandler(testButton_KeyPress);
this.KeyDown += new KeyEventHandler(testButton_KeyDown);
this.FormClosing += new FormClosingEventHandler(testButton_FormClosing);
this.components = new System.ComponentModel.Container();
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(frmMain));
this.openDialog = new System.Windows.Forms.OpenFileDialog();
...
}
void testButton_KeyDown(object sender, KeyEventArgs kea)
{
switch (kea.KeyData)
{
case Keys.Left:
...
break;
case Keys.Right:
...
break;
}
}
}

List of keycode

*: 59 in firefox
**: 61 in firefox