Your script does not make much sense to me but it is possible to put two graphs into one page using << journal.
plot1=tbl1< Y( :age ), X( :height ) ); plot2=tbl2< Y( :age ), X( :height ) ); plot1<plot2< If you don't mean "page" as in page, but rather a custom report, then I think you must define the variables for the tables and individual reports outside the VListBox-object. Thereafter you can use your reports or elements within them to make a custom report.
You do not need the << journal commands if you indend to use the NewWindow-command (the << journal creates a new window automatically, unless you already have a journal open), and in anyway I don't think you can use <
Try this (the < dt=datatable("name of your data table"); wind = New Window( "Agency Analysis Window",