How to refer to the datatable from which script was done?

[#1]

This might be a stupid question, but how do I refer to the datatable from which I ran the script if I dont know what the table name it is save as before hand?

In most solutions in the forum the script starts with something as:

dt = Open( "$SAMPLE_DATA/Big Class.jmp" );

and then you can do things to dt like 

dt << NewColumn( - - - -

But what if I want my script to just run asuming dt is whatever table from which the script was run?

[#2]

If you are sure it will run against the table that was active when the script is started you can use the current data table:

dt = current data table();