(misc)
boolean o2zero(string $view_name, string $field_name)Returns boolean value TRUE/FALSE if field value is equal/different from its type default value.
This function is the right way to check if a field or variable has a value.
When the view is a db-view it must be defined in the program where o2zero() is used and the field must be a field defined in that view.
To check a program-variable value pass JX_VIRT_VIEW as view name.
To check an application (session) variable pass "_o2SESSION" as view name.