SSRS Expression

i've got a report that contains a group total.
i have a percentflag - H = time. Y = precent. N = number.

=iif(fields!PercentFlag.Value ="H",format(fields!Time.Value, "HH:mm"),Iif(((Fields!PercentFlag.Value ="Y") AND (Fields!Value.Value >0)),Format(Sum(Fields!Value.Value *100), "0.0")  & "%",
Iif(((Fields!PercentFlag.Value ="Y") AND (Fields!Value.Value <0)),Format(Sum(Fields!Value.Value *100), "0.0")  & "%",
Replace(cStr(Sum(Fields!Value.Value)),".0",""))))

the problem is my totals are not correct.

they are being displayed as.
N = ok
Y = 0274433
H = nothing being displayed.