data conversion error

I have code:
            iSQL = "insert into session  (date,start_time,end_time,fid,cid,location,notes) values ('"             iSQL = iSQL & txBoxDate.Text & "','" & txBoxStartTime.Text & "','" & txBoxEndTime.Text & "'," & txBoxFid.Text & "," & _                     txBoxCid.Text & ",'" & txBoxLocation.Text & "','" & notes & "')"

data type for date is date, start_time is time(7) for both sql express and sql server.  It runs fine with sqlexpress, but sql server gives error "Conversion failed when converting date and/or time from character string.&q ...