Numbers Identifying Selected Table

tell application "Numbers"
    activate
    try
        if not (exists document 1) then error number 1000
        tell document 1
            try
                tell active sheet
                    set the selectedTable to ¬
                        (the first table whose class of selection range is range)
                end tell
            on error
                error number 1001
            end try
            tell selectedTable
                -- editing statements go here
            end tell
        end tell
    on error errorMessage number errorNumber
        if errorNumber is 1000 then
            set alertString to "MISSING RESOURCE"
            set errorMessage to "Please create or open a document before running this script."
        else if errorNumber is 1001 then
            set alertString to "SELECTION ERROR"
            set errorMessage to "Please select a table before running this script."
        else
            set alertString to "EXECUTION ERROR"
        end if
        if errorNumber is not -128 then
            display alert alertString message errorMessage buttons {"Cancel"}
        end if
        error number -128
    end try
end tell