Update custom field in portfolio

[lpb]

This is a duplicate question; already answered in this thread:

Roll Up Custom Field - Portfolios

Hi Larry Just to ensure I understand this correctly, the roll up custom field in the project portfolio will add up all cost fields in a projects tasks? As long as the cost field is set to global in project. So if I have three tasks in a project each with a cost field of $500, the roll up custom field in the portfolio should show $1500? Many thanks Alex