IF function issue

I had a bad post title so I started a new post because I couldn't figure out how to change the title or delete that post.

I need help with a formula. Cell e22 has 9 in the cell. In cell e23 I want a formula that does this: If cell e22 is greater than 8 subtract 8 from that amount (9-8) and then multiply that by 255 (1x255), if there is nothing in e22 then I don't want anything in e23. Make sense? I have tried both of the following formulas
=IF(E22>8,E22-8,E23="")

=IF(E22>8,E22-8,"")
I am not sure what i am doing wrong can anyone help me?

Dredwolf's summary is a little more complicated, in that cell E23 will be blank if E22 is blank also. I do that for almost all spreadsheets I set up, because it's neater when you don't have data entered.

But to have the "bare bones" equation, just =IF(E22>8,(E22-8)*255,"") will do what you ask.