Need help with complex IF formula I guess?? :)

Attachment 455946

Hi,
I've tried for days to get this right, but I can't figure it out, and desperately need some help.

When row 1 is between 0 and 30, row 4 should be 1 until row 1 goes over 50, at which time row 4 turns to zero.
When row 1 is between 70 and 100, row 4 should be -1 until row 1 goes belove 50, at which time row 4 turns to zero.

Please see row 4 (values only) to understand. I need to write a function that can fill out row 4 automatically.