need responsive menu only on mobile

have twenty eleven theme. have a menu now that goes across the top. but it is not responsive on mobile devices. So I added the responsive menu plugin. I have it working on mobile devices, and put in the name of current menu so it would hide it, but now it hides it on the website completely. Is there a way to have the responsive menu ONLY if it is on a mobile device and the regular menu on desktops?

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