Conditionally hiding panels (edit/detail views) based on other field.

[LaFortuna]

After browsing many threads on the subject, I'm still not sure on the correct way to hide/display panels based on a dropdown value. Is the DevToolKit still good for SugarCRM CE 6.4?
Basically what I want to do is display a panel about the reasons for loosing an opportunity if the sales stage is "Closed Lost". What would be the best approach, keeping in mind that there is already some javascript that handles the sales probability field?

[GregoryCollett]

Hello LaFortuna,

Yes, the devtoolkit will probably be the easiest option.

I have recently done this on my ce6.4 using the devtoolkit.

Regards,
Greg