ContributionsMost RecentMost LikesSolutionsRe: IsNull doesn't work with the required fields Thank you for your answer. So this is another bug workaround. It allows you to keep the fields required at the level of its properties, but it forces adding "unnecessary" fields to the entire table. Do you know if and when this bug will be fixed in QB? ------------------------------ Jacek Lewandowski ------------------------------ Re: IsNull doesn't work with the required fieldsThis error occurs when you first fill in the date field and then delete the value from that field. ------------------------------ Jacek Lewandowski ------------------------------ Re: IsNull doesn't work with the required fields It's not answer for my question. As I wrote in the first post, this is just a fragment of the formula. I do not use this field to inform the user that he has an empty required field, because it is a basic QB functionality and there is no point in duplicating it. I use this calculated field to create JSON which is later used in js which is loaded into the form. Therefore, it needs that if the required field is not completed, the IsNull function will work and I will be able to write to JSON that this field is empty. At the moment, QB is generating an error and does not display the calculated field at all. ------------------------------ Jacek Lewandowski ------------------------------ Re: IsNull doesn't work with the required fields On the form, I can delete data from the field, or still not complete it when adding a new record. ------------------------------ Jacek Lewandowski ------------------------------ IsNull doesn't work with the required fields Hi, I have a problem with the "IsNull" function and the date field. My date field "Assignment End Date (DD-MM-YYYY)" is required and of course it is visible on the form. I also have a formula - Rich Text field with formula (finally the formula is longer but I shortened it to check the IsNull function): var text assignmentEndDate = If(IsNull([Assignment End Date (DD-MM-YYYY)]),"Is NULL","Not NULL"); $assignmentEndDate The field with the formula is visible on the form. We have two case: The "Assignment End Date (DD-MM-YYYY)" field has a value, and the formula field text is "Not NULL" - Correct The "Assignment End Date (DD-MM-YYYY)" field is empty, then QB does not generate this field in the DOM, and instead only shows "???" -Not correct I was able to work around this problem on the form by removing the required property from the "xxx" field and selecting it in the form itself to make it mandatory. After this procedure, QB correctly calculates the formula. However, this is not a good solution because this field must be required in the entire system, not only on one form. How do I use the "IsNull" function on fields that have the Require property set? Best Regards Jacek ------------------------------ Jacek Lewandowski ------------------------------