Sum on 2 tables

Hi,

I want to retreive the sum of 2 numbers that are located in 2 different tables.

Both the field names are the same, from the tables i wish to retreive the data from:

Something like this:

Table: ocd_campaigns_cost
modelid total
5 350

Table: ocd_campaigns_cost_tot
modelid total
5 121238

I wrote this query (asp):

SQL_SUM = "SELECT [ocd_campaigns_cost.totale kosten],SUM([ocd_campaigns_cost.totale kosten]) - SUM([ocd_campaigns_cost_tot.totale kosten]) AS SUM_KOSTEN FROM ocd_campaigns_cost LEFT JOIN ocd_campaigns_cost_tot ON [totale kosten] = [ocd_campaigns_cost_tot.totale kosten] WHERE ocd_campaigns_cost_tot.modelID = " & request("ModelID") & " AND ocd_campaigns_cost.modelID = " & request("ModelID") & ""



But all it does is return:
Microsoft OLE DB Provider for ODBC Drivers error '80040e14'

[Microsoft][ODBC SQL Server Driver][SQL Server]Ambiguous column name 'totale kosten'.

/OCD/campaign/graph.asp, line 84


Can you guys please help me?

This part of your SQL statement:
FROM ocd_campaigns_cost LEFT JOIN ocd_campaigns_cost_tot ON [totale kosten] = [ocd_campaigns_cost_tot.totale kosten]

should be (my changes in bold font):

FROM ocd_campaigns_cost LEFT JOIN ocd_campaigns_cost_tot ON [ocd_campaigns_cost.totale kosten] = [ocd_campaigns_cost_tot.totale kosten]