Colspan not supported

I want to have a table like below, so that the secondary row spans both columns.

/==============|============\
| Name         | City       |
|---------------------------|
| My personal message, yay! |
\==============|============/

But instead it show me this. The HTML isn't even correct because it's missing the last TD.

/================|=============\
| Name           | City        |
|----------------|-------------|
| My personal    |             |
| message, yay ! |             |
\================|=============/

In this example I'm using two fields for the first row and one field for the second row. I'd like to be able to use three or four fields for the first row.

Does anyone have a idea how to fix this? I think it's just a matter of adding a option to select the number of cols you want the secondary field to span.