Can anyone pls help me with this code.

Sub Validation()
If CheckBox1.Value = Checked Then
Worksheets("Form").Range("F_Name").Enabled = True
Else
Worksheets("Form").Range("F_Name").Enabled = False
End If

End Sub

I have written this code for a check box. If the check box is checked
then a cell named F_Name should be able to take in values entered. If
the check box is not selected then the F_Name field should be
deactivated or greyed out so that no values can be entered.

The code above throws a run time error '438': Object doesn't support
this property or method.

Can anyone help me fix this.. is this a code error or Excel property
that needs to be changed

Thanks in advance for you help.