error called to undifined method when using pop()

I'm trying to add the pop function t开发者_StackOverflow社区o a button in flex 4. But I keep getting an error call to undefined method when I try to use it, but it's a built in function isn't it? I posted my code below, any ideas?

    <s:Button x="405" y="410" label="Undo last" width="85" click="data.pop()" id="undo"/>

data.pop() most likely won't work unless you are using your button as item renderer or item editor in a DataGrid.

In case you defined a variable of type Array called data try to rename it to something else. data is used by the framework itself.