1-Build a form 2-use a Zoho sheet to calculate solution 3-Send back solution on the form ** At the present time I use Editgrid.com. With this solution, multiple users can simultaneously use the sheet : they all have their own session (opposate to collaborate) On zoho sheet different users using the sheet interfere with each other : i don't want that. ** I want a form abble to use a Zoho sheet and send back solution I am doing the sheet (non visual basic), frequent change on it but always same output There can be several person in the same time (1 to 5) on the form. ** Online demo at http://patrimoine.vertdurable.com/simulateur/simulateur.html