node history trigger message.

It's possible through a SQL macro in the trigger message. You will have to query the Events table to get this number. I  curious why you would want this is an alert as it seems more appropriate for a repor.

You can view this information on your 'Event Summary' as well (When you login into Solarwinds Web Portal , Home -> Event Summary

Select the Node Name that you want to pick on, hope it helps. If you are already aware of it please ignore my message

yes but Im trying to figure out how I could put it on advance alerts in my message.

I know a report would be nice. but the people in my area usually wont act until they actual see the message from the node down.

Since the data has to be calculated, there's really not going to be a way to easily get that value.  You'd basically have to build a SQL variable that contains a query that returns the number of events for that specific node, and only returns the count, and nothing else.  It would look something like this:

Select COUNT(Events.EventID) From Events

Join Nodes on Events.NetworkNode = Nodes.NodeID

Where EventTime >= DATEADD(day, -30, GetDate())

AND

EventType = 1

And Nodes.NodeID = ${NodeID}

But again, you'd have to use the Build SQL Select option and then put the above query in it.  This isn't a guarantee that it will work, but that would be about the only way to get it into the message.