Approve List Items

<input name="btnSelectAll" onclick="SelectAll()" type="button" value="Select All"/>
<input name="btnShowRibbon" onclick="showItemTab()" type="button" value="Show Ribbon"/>
<input name="btnDeselectAll" onclick="DeselectAll()" type="button" value="Deselect All"/>
<input name="btnApprove" onclick="Approve()" type="button" value="Set Approve"/>
<script type="text/javascript">
function SelectAll()
{
DeselectAll();
for(var i=0;i<ctx.ListData.Row.length;i++)
{
SelectRowByIndex(ctx,i,true);
}
}

function DeselectAll() {
  var clvp = ctx.clvp;
  var tab = clvp.tab;
  DeselectAllItems(ctx,tab.rows,false);
}

function showItemTab(){
 ribbon = SP.Ribbon.PageManager.get_instance().get_ribbon();
 SelectRibbonTab("Ribbon.ListItem",true);
}

function Approve()
{
  if(confirm('cofirmation message'))
  {
   var context = new SP.ClientContext.get_current();
   var selectedItems = SP.ListOperation.Selection.getSelectedItems(context);
   var list = context.get_web().get_lists().getByTitle("Test Approve Items");
   var item;
  for (item in selectedItems)
  {
    var listitem = list.getItemById(selectedItems[item].id);
    context.load(listitem,"Status");
    
    if(listitem!="")
    {
     listitem.set_item("Status","Approve");
     listitem.update();
    }
   }
  context.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));
 }
}

function onQuerySucceeded()
{
 console.log("Item approved");
}

function onQueryFailed(sender, args) {
  alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
}
</script>