Altering invisible Rows in a Table

Hi,

I face the following problem; I have a table with checkbox in a column and want to create a toggle (select / deselect all)

I started like this:

var rows = detailTable.getRows();

for(var k=0;k<rows.length;k++) {

     var thisRow = rows[k];

      ...

     thisRow.getCells()[0].setChecked(false);

}

I though it was an elegant way, but first thing, what I noticed, it that the loop may contains more rows then my model (when I made more rows visible), or less (then I may scroll, but the boxes I don't see aren't toggled..); and that's the problem, does someone have an Idea?

Greetings,

Michael