Fixing a Formula

I need the formula in the B:C cells to display values that are negative from the second tab. I got it started, but I'm not sure where I'm going wrong. I don't want it to display the #value! errors.

Commission Sheet 051713.xlsx

try to put error trapping, IFERROR()
=IFERROR(IF(MonthSel="","",IF(OR($E$1="",ROWS(B$5:F5)>COUNTIF(INDEX('Monthly Formulas'!$B$28:$M$34,0,MATCH($E$1,'Monthly Formulas'!$B$1:$M$1,0)),"<>0")),"",INDEX('Monthly Formulas'!$A$28:$A$34,-SMALL(INDEX((INDEX('Monthly Formulas'!$B$28:$M$34,0,MATCH($E$1,'Monthly Formulas'!$B$1:$M$1,0))<>0)*(-ROW('Monthly Formulas'!$B$28:$M$34)+ROW('Monthly Formulas'!$B$28:$M$28)-1),),ROW(A1))))),"")

Awesome, that works, thank you so much!