cfchart seriersPlacement

["Lei Hu"]

I try to make two series stacked on each other, but the chart displays the two 
lines side by side.  HOw can I get them stack on each other?  Thanks in advance.

 Here is my code: 

 <cfquery name="getrec" datasource="testdata">
 Select * from charttest where date_time='December'
 order by salinity
 </cfquery>

 <cfquery name="getrec1" datasource="testdata">
 Select * from charttest where date_time='January'
 order by salinity
 </cfquery>

 <cfchart 
           format = "jpg" 
                xAxisTitle="Salinity"
                yAxisTitle="tem"
                font="Arial"
                gridlines=7 
                showborder="yes"
                seriesPlacement = "stacked" 
                chartHeight = "400"     
                chartWidth = "500" >
        <cfchartseries 
                type="line" 
                query="getrec" 
                valueColumn="tem" 
                itemColumn="salinity"
                seriesColor="olive" 
                paintStyle="plain"
        />
        <cfchartseries 
                type="line" 
                query="getrec1" 
                valueColumn="tem" 
                itemColumn="salinity"
                seriesColor="red" 
                paintStyle="plain"
        />
 </cfchart>