form/GridElementCells A string that defines the number of used cells in a <code>GridLayout</code>. This can be a number from 1 to 16, "auto" or "full". If set to "auto" the size is determined by the number of fields and the available cells. For labels the auto size is 3 cells. If set to "full" only one field is allowed within the <code>FormElement</code>. It gets the full width of the row and the label is displayed above. <b>Note:</b> For labels full size has no effect. auto|full|([1-9]|1[0-6])