halu. im a newbie
i used datagrid to place multiple tables w/ corresponding data from the database
i could update the first table and it saves into the database what i've change but when i'm going to update the second table it gives me an error: missing the datacolumn "code" in the Datatable 'gallons' for the SourceColumn 'code'
i dont know how to figure it out.

Code:
dim cn as new sqlconnection("......")
dim cm as new sqlcommand()
Private ds as new dataset()
dim da as new Sqldataadapter()
dim cmdtext as string

'form load

cn.open
cm.connection=cn
cm.commandtype = commandtype.storedprocedure
cmdtext = "select * from customertable ; select * from gallons"
da.selectcommand = new sqlcommand(cmdtext, cn)
da.tablemappings="Table","Customer"
da.tablemappings="Table1","Gallons"
da.fill(ds)
datagrid1.datasource = ds

'to save the changes

if ds.haschanges then
    dim cb as Sqlcommandbuilder
    da.selectcommand = new sqlcommand(cmdtext,cn)
    cb = new sqlcommandbuilder(da)
    da.Update(ds,"Customer")
    da.Update(ds,"Gallons")
end if
tanx in advance....