Hi,

There is a way on single expand mode. In single expand mode, expanding one item would collapse other expanded item, so you wouldn't have multiple items expanded at the same time.

In order to use this feature, set SingleExpand to "True" (which is the default value) and ExpandOnClick to "Disabled".

The reason that this feature is only enabled in "single expand" mode is because, in "mulitple expand" mode, the slide menu never automatically collapse an item (as oppose to automatically collapsing the current expanded item when user expand another item in single expand mode); so user need a way to explicitly collapse an expanded item. If we allow expand to be triggered by onmouseover, then collapse has to be triggered by something else (It can not also be onmouseover because onmouseover happens too often and if onmouseover were to be used, you would see it keep expanding/collapsing when you move mouse over the item). This will cause quite some confusion among end users.

Thanks