Apps Problem with Grid View

I wanted to create a grid view from the tutorial from this web site : Grid View | Android Developers


And the problem i got was when i should write in which pictures that should show i wrote this as the tutorial said:

private Integer[] mThumbIds = {
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7

But i got this error message : Cannot be resoloved or is not in a field

Any ideas or help here?

 

Err.. Thanks..