Write Empty Expression

Hi,
I want to control a text field if it is empty like for example : /data/my_field <> "". I would like find a better expression of comparing an empty field. This is to control the require text field with my own message

In CommCare you check if a field is empty by checking if it is equal to the empty string, so:

/data/myfield = ''

will return true if the field is empty, and false if it is non-empty

Thanks Aliza for your support