Use a button with SELECT elements to perform an action
Make sure drop down menus options are not triggered until a button is activated
Select drop down (combo box) menus are infamous for triggering unexpected actions, as soon as one of their options has focus set to it. Given how popular the behaviour has grown over the years, authors might be led to believe that this is a recommendable approach. Authors who are mindful of their users’ experience will let users control when an action is performed, rather than having the action occur as a side effect of choosing a value for the select element. This way, inspecting the different values of the select element, or accidentally choosing the wrong value will not unexpectedly cause the action to occur. Instead, the trigger will only be called into play when users are satisfied with their choice and select the button to perform the action.
To do so, simply make sure scripts are not used to trigger the SELECT option as soon as focus is set to it. Provide a submit button next to the drop down menu, so users ultimately end up being the ones deciding when information is going to be processed. This [...]