multivalue error

Hi,

I am looking to sum the value based on the below defined variable but its giving #MULTIVALUE Errors,

i even tried ForEach function ----  =Sum([Amount]) ForEach([agree_type_desc])

When i tried with agree_id, agree_type_desc, amount its works, but i want amount for each agree_type_desc.

=If([Customer Name]="20th Century" And [count_20th Century]=1) Then [Amount]*0.5
ElseIf([Customer Name]="20th Century" And [count_20th Century ]>1) Then [Amount]

ElseIf([Customer Name]="IMO") And [Dept]="Account" And [count_IMO]<=2 Then [Amount] ElseIf
([Customer Name]="IMO") And [Dept]="Account" And [count_IMO]>2 Then [Amount]*0.7

ElseIf([Amount]<358.4) And [[Customer Name] ="Bl Man" Then [Amount] ElseIf
([Amount]>358.4) And [[Customer Name] ="Bl Man" Then [Dummy Number 1]*363

ElseIf([Customer Name]="LEI") Then ([Amount]-[disc_LEI])

ElseIf([Customer Name]="BOYRS") And [Dept]="GAME" Then [Dummy Number 1]*363

ElseIf([Customer Name]="Braves" And [Dept]="SALES") Then [Amount]*0.85

ElseIf([Customer Name]="RILS") And [count_RILS]<=75 And [[Close Date] >= '01/09/2014' And [Close Date]<= '31/05/2014'
  Then ([Dummy Number 1]*75*998/[count_RILS])
ElseIf([Customer Name]="RILS") And [count_RILS]>75 And [Close Date] >= '01/09/2014' And [Close Date]<= '31/05/2014'
Then [Dummy Number 1]*998

ElseIf([Classification]="GROUP") Then [Amount]
ElseIf([Classification]="INDE") Then [Amount]

Thanks

Shaikh