How to create a SQL Server perfomance condition alert for all databases and call a job?

When I create a SQL Server  perfomance condition alert, the wizard asks for a database to apply. But I want create an alert not for one, but for all databases wich logs sizes excceeds 80% of  it´s maximum size. The SQL Server event alert wizard has the option to choose all databases, but the SQL Server  perfomance condition alert wizard doesn´t have. After, I´d like that this alert calls a job that receives the name of the database and execute it´s full log backup.