Trouble with Modified By using a Custom Button

Trouble with Modified By using a Custom Button

Hi,

I'm using a custom button with a custom function that send some data from quotes to sales orders.

The problem is that we have 5 users.
If the user 1 executes the button, in the sales order it says that it has been modified by me (the super administrator, who has done the custom button).

Is there any way to prevent this from happening and leaving as modified by the user who has executed the button?

Regards,