BI Publisher rtf template date null condition

In an .rtf template for BI Publisher i want to show a text depending on a date.

example:

<?if@inlines:MEETING_DATE!=''?> Text when there is a meeting date <?end if?>
<?if@inlines:MEETING_DATE=''?> Text when there is no meeting date <?end if?>

The first line is working perfectly. When a date is found, it shows the desired text. But the second line doesn't work. The second text should be shown when the date field is empty. But at the moment nothing is shown in that case.

As an alternative, I tried the following:

<?if@inlines:MEETING_DATE=null?> Text when there is no meeting date <?end if?>

But that isn't working either.

How can I show the second text when the date field is empty?