I have code which displays a user form when a particular cell is activated.
The user may then select a value from a list box in the user form which then
appears in that cell. The user form then unloads when OK/cancel button in
User Form is selected.
However, the user may activate that cell and then choose not to update the
cell value. In this situation I would like the user form to unload without
the user having to click any button/control in the user form but merely by
hitting any arrow key in the keyboard.
Any help would be much appreciated.

The code currently is:

In sheet module:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Address = Range("xxxx").Address Then
SelectAccount
Else: Unload UserForm1
End If
End Sub

In main module:
Sub SelectAccount()
UserForm1.ListBox1.RowSource = Range("xxxxList").Address
UserForm1.ListBox1.ControlSource = Range("xxxx").Address
With UserForm1
.Show vbModeless
.Move 450, 100
End With
End Sub

The code attached to the OK/Cancel buttons is just:
Unload UserForm1

Thanks,
Partho