How can I changing zIndex dynamically

I initially set the z-index to -1
<style type="text/css">
#myGrid {height: 150px; width: 792px; z-index:-1}
#myGrid .aw-column-1 {border-right: 1px solid #ccc;}
#myGrid .aw-column-2 {border-left: 1px solid #ccc;}

</style>

I like to change the zIndex value
<script type="text/javascript">

var mySelector = ["Identification Number:", "Type:", "Name:"];
var myTips = ["the XG Device Identification", "Type of Device Base Station or Subscriber station"];
var grid = new AW.UI.Grid;
grid.setId("myGrid");
grid.style.zIndex = 1000;
grid.setSelectorVisible(true);
grid.setSelectorWidth(200);
grid.setSelectorText(mySelector);
grid.setSelectorTooltip(myTips);
grid.setFixedLeft(1);
grid.setCellData(function(col, row){return "cell " + col + "." + row});
grid.setColumnCount(1);
grid.setRowCount(10);
grid.setHeaderHeight(0);
grid.refresh();
grid.style.zIndex = -1;

</script>

You should use setStyle() method -

grid.setStyle("z-index", 1000);

Thank Alex.

By the way, I purchased your product (very nice) and implementating it for AppWeb. I will let you know how is going.