// this function show / hide table rows
// Parameters:  table_id
//              rows_ids (array of row_id to show / hide)
//              visible (boolean, true -> show rows, false -> hide rows)
function setTableRowsVisible(table_id, rows_ids, visible) {
    if (navigator.appName == "Microsoft Internet Explorer") {
        var displayType = 'block';
    } else {
        var displayType = 'table-row';
    } 
    for (var i = 0; i < rows_ids.length; i++) {
        if (visible) {
            document.getElementById(table_id).rows[rows_ids[i]].style.visibility = "visible";
            document.getElementById(table_id).rows[rows_ids[i]].style.display = displayType; 
        } else {
            document.getElementById(table_id).rows[rows_ids[i]].style.visibility = "hidden";
            document.getElementById(table_id).rows[rows_ids[i]].style.display = "none";    
        }
    }    
}