Well, not to ask a dumb question, but why do you need onclick on both the image and the <a> element???
Why not just stop using the onclick in the <img> when it's part of an <a> and instead use the <a>'s own onclick handler to perform both functions? If the user asks for help, you give it and return false. If not, you return true to allow the <a>'s href to activate.
But, yes, you *can* cancel "bubbling" so that the inner onclick is not seen by the outer element.
Google for "hot to cancel bubbling".
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