Display of Attention Checks after a Randomized Block

Put all the 8 blocks in 8 diiferent group. Create an embedded data i and set its value to 0. Now in each group after displaying the block increment the i value using math operation. After this, in the same group check if its value is equal to 1 then its block which appeared first and then again check if i is equal to 8 then its the last block and show them the attention check respectively.
So the survey flow will be similar to below:
Set Embedded data i = 0
Randomizer
Group 1:
Block 1
Increment i: i = i + 1
if i = 1
 Attention check wrt scenario 1
if i = 8
 Attention check wrt scenario 1
 Group 2:
Block 2
Increment i: i = i + 1
if i = 1
 Attention check wrt scenario 2
if i = 8
 Attention check wrt scenario 2
 .
.
.
Group 8:
Block 8
Increment i: i = i + 1
if i = 1
 Attention check wrt scenario 8
if i = 8
 Attention check wrt scenario 8