Tricky Tips of IFortran

Don't know why but some tricky things - small but rather annoying if neglegence:

1. character(len=xx) :: stringwrite(unit = string, '(A)') i
Note: xx SHOULD BE LONGER than 12...

2. use open(unit=xx, file=xx, form='UNFORMATTED') rather than open(unit=xx, file=xx, form='BINARY') if you want to read the file.
in my program, backspace() was used, which caused troubles with the Binary format
don't know why, but frustrating me for almost a whole day!!