Oracle Forms

I'm a newby in Forms.
I've created a form based on a view based on two tables.
To use this view for inserting values I've used succesfully an instead-of-trigger.
What I don't know how to do is how to report a combo box for one of the values.
I try to explain by an example.
Let's suppose to have a PERSON table (name, sirname, age, ...) and a GENDER table (id_gender, gender_description) where gender_description is Masculine or Female
My view is made of all of the columns of PERSON and gender_description of GENDER
When the form allows me to insert a new person, I'd like that in the field of gender_description it were reported to me a combo box with Masculine or Female so as to permit to me to choose and then the instead-of-trigger will insert into the PERSON table the new values of name, sirname, age + id_gender (which is a foreign key to GENDER table).
What and how to use for getting a combo box? LOVs or what else and how to create it?

Thanks in advance!