IF Function when formula copy to another cell, shows #value , would like to show 0

I am not that good at excel, I am working on this file cell F63 has no value, on cell G63 shows #value, would like to show 0 value in G cell, and same thng in cell I12 , i already have formula , would like to change #value to 0, what formula I can add to fix this, Please Help.

I have attached teh file , the one Highlighted in RED.

Thanks in advance for Help.

For the " RED" cell,try.

=IFERROR(IF(G15=0,"",(G15-H15)),0)

Thanks a Lot, its worked, what i was looking for, you guys are great.