need cond format to change row colour on change of unique id - this? =MOD($A1,2)=0

How can I use conditional formatting to give me this:
(at each change of unique ID in col A-change the entire row colour)

id (colA) value (colB)
1 abc
1 abc
1 abc
2 efg
3 hij
3 hij

I found this on the net but isn't working reliably =MOD($A1,2)=0

Dave

1. Select the first row and extend your selection below upto the last row of the Column-A data
2. Choose Home|Styles|Conditional Formatting
3. Click New Rule
4. Choose the option Use a formula to determine which cells to format
5. In the formula box, enter
=COUNTIF($A:$A,$A1)<>1
6. Click the Format button.
7. Select a Font color or Fill color to ORANGE.
8. Click OK, Ok, Apply, Ok.

Hope this helps!