I have developed a form where the user can manulaly enter data. I am trying to validate
the fields and to put a message if the criteria is not correct. How can I show for
example which field is missing details (name of field) so that the user knows where to input details and also to put a cursor on that field on a form

You can use SetFocus to move the cursor to the field.

May want to think about changing the background color of the Controls that are missing data.