Flash Actionscript3: How to reset datagrid between frames

I use ActionScript3 in Flash Professional to build an animation in multiple frames.

The user has forward and back buttons to navigate between frames. At a certain time, I introduce a datagrid (inserted from the editor) fill it with data and everything goes OK.

//Example frame 9

stop();

r7.removeAllColumns()

r7.addColumn("column1");
r7.addColumn("column2");
r7.addColumn("column3");

r7.addItem({column1:"A", "column2":"a1", "comumn3":"1"});
r7.addItem({column1:"B", "column2":"b1", "comumn3":"1"});

But each time the user goes back to the previous frame (frame 9) from (frame 10), the datagrid is refilled with the same rows again.
I used removeAllColumns() because without it, the same columns are appended to the existing ones.

Still the issues of rows not solved.

Here is the illustration:

frame9 from frame8:

frame9 from frame10:

Neither removeAll() alone nor removeAllColumns() alone will work.

• removeAllColumns(): removes columns (obvious).
• removeAll(): removes only rows, which is not obvious according to documentation.

This is what solved my issue:

r7.removeAll();
r7.removeAllColumns();

Here is the tests:
1- Using only "removeAll()"

2- Using only "removeAllColumns()"

3- Using both "removeAll()" & "removeAllColumns()"