performance problem when using grid with checkbox

Hello, I am using the grid with checkbox. And I put a checkbox on the head to select all rows.
Usually it need 10s and 100% cpu to select all rows when the grid have 4000 rows which can not be accepted. And I have keep virtual mode on .

The code is as following. Is there any way to improve the performance?


obj.checkboxSellAll.onControlValueChanged = function(value){
     var obj=null;
         obj= eval($("currentGridName").value);
         if(value){
                 var rows_array = new Array();
                 for(var i=0;i<obj.tabGrid.getRowCount();i++){
                 if (obj.tabGrid.getCellText(obj.idColIndex,i)!=''){
                 rows_array[i]=i;
                 }
                 }
                 obj.tabGrid.setSelectedRows(rows_array);
                }else{
                 obj.tabGrid.setSelectedRows([]);
             }
         }

Help! Please.

Joseph,

maybe this can help -

http://www.activewidgets.com/javascript.forum.16116.9/select-all-rows-performance-problem.html

Thank Alex!