'&' in an if statement is for the test only, the value is not affected

tmp = x
tmp = (val >> n) & 0x01; /* isolate the bit */
tmp STILL =x

However, for let's say n = 2, after the first line : 

tmp = 0000 0110 & 0x01 ; -> 0000 0000 
hence, the next line again check, 
if((0000 0110 && 0000 0001) != 0)

So for this case, the result is NOT '0'

if the above was not the case, you could not do this:
if (ralph & 0x01)
{
...
)
else if (ralph & 0x02)
{
...
)


erik