Is it possible to multiple values of 2 fields

Hello ggppdk,
I know i am very bad. But step by step i progress.
I searched during all morning , I did exactly what you told me in your last message but without result.
After 2 steps i must make another thing ?

Hello

I searched during all morning ,

It would take me 5-10 minutes to configure this

Is the website live or under development ?
- Please give me access to the website

Tell me
- the 2 fields that need to be multiplied
- the field that will contain the multiplication


Do you want to try the new beta version that support automatic value creation and storage in DB ?
- it provides much more flexibility because you really have the result stored in DB and you can even use field in filtering form

Thank you to help me ggppdk.
The site is under developpement.
I try to make a site in order to improve my job. Programmation is not my job but i like this and i try the evening at house. I learn in the same time.
And I am french so perhaps i don't understand all your explications.
I can try with the new beta version for not always ask your help.

The site is under developpement.

If site is on an online server

- Please give me access to the website

Tell me
- the 2 fields that need to be multiplied
- the field that will contain the multiplication

It's not possible because the server is on my plant. I have not possibility to give you the acces.
I attache the picture of fields.

In the file default_new.php (copie of value_defaut.php ) i copy

$field->{$prop}[$n] = $item->fieldvalues[48][$n] * $item->fieldvalues[49][$n];

instead of : $field->{$prop}[$n] = $item->fieldvalues[45][$n] * $item->fieldvalues[54][$n];

Hello

you used the correct field ids and it is working now ?