Checkbox option adds value to total

when customers make a checkmark in the the text box for "avec changement" or "sans changement" the price appears autmatically. is it possible?

Please provide more details on the desired result. Will it have a calculation associated? If so how is it performed?

But you can add a Form calculation and then add calculation values to the checkbox field so that it retrieves a value upon selection. You can test it here:

http://form.jotformpro.com/form/51066045906958? 

Let us know if we can assist you further.   

Good!!

with this form (when client select a quantity the other choices are frozed)) i want what you did with this form.  Yes it need a calculation at the end.

http://form.jotformpro.com/form/51066079925966

In that case you can add a form calculation widget:

Add calculation values to the checkbox or radio button fields:

These values will not be seen but will be used in the calculation field.

Now you just need to add the checkbox field to the calculation field:

You can clone the demo form to inspect it further:

http://form.jotformpro.com/form/51066045906958? 

Let us know if we can assist you further.   

Can i clone your part and add it to my form?

Unfortunately it is not possible to clone fields with conditions and calculations from one form to other. You can follow instructions provided by my colleague to make calculation inside of your form.

It is possible only to clone fields without conditions by using Field Manager.

More about how to perform calculation in the form you can find in this article:

http://www.jotform.com/help/259-How-to-Perform-Calculation-in-the-Form 

You can clone mentioned form http://form.jotformpro.com/form/51066045906958?  to see how calculation are set inside of the form. 

Hope this will help. 

Yes i know and i am not able to do it correctly i think... it's not working like your colleague. Here is my form below, can you help me with this part ?

http://form.jotform.us/form/51095212553146

In order for us to help you achieve the desired results please let us know which fields are you trying to update.

Is it the repeat with/out modifications? What are the associated values? Which fields are they going to update?

We'll wait for more details to proceed.

In this form below

http://form.jotform.us/form/51095212553146

This part below

It is not possible to pass filed values to drop down field. Instead of drop down field you can add calculation widget and than pass values from check box field to calculation field. 

You need to add  Calculation values to check box field.

These values will not be seen but will be used in the calculation field.

Now you just need to add the checkbox field to the calculation field:

Also you can rename the label of calculation widget.

Here is clone of your form that I have change.

http://form.jotformpro.com/form/51095045550955? 

Hope this will help.