Dear statalist,

I have a variable, index, its value should be between 0 to 1, but there are some values out of this range, so I want to set those values as .
I tried
Code:
replace index==. if index<0|index>1
but that doesn't work. replace index=. doesn't work either
It seems I could replace index with any real value but not .

Any help will be greatly appreciated!