adding row to grid after sorting

Dear All,

I'm using the following function to add rows to the grid:

function new_row() {
alert(data1.length);
obj.setRowProperty("count", obj.getRowProperty("count") + 1);
data1[data1.length] = ["CCCC", "Synopsys, Inc.", "4535", "186", "4254"];
bj.refresh();
}

This function works, but after I clicked on column header to sort. I can't add rows anymore to the grid ?

Anyone a suggestion ?

Thanks in advance !

Chris