Applescript - trying to horizontally align all the text in a text frame

Question

I've tried the following snippet along with several others:
tell application "Adobe InDesign CS5.5"
          tell the active document
                    set Text_Frame to the text frame "PH"
                    tell Text_Frame
                              set theLines to every line
                              if (theTextPos = "B") then
                                        tell theLines to set justification to left align
                              else
                                        tell theLines to set justification to center align
                              end if
                    end tell
          end tell
end tell
Throws errors about setting classes.
ie
error "Can’t set «class paln» of {\"MISSOULA COMMUNITY PHYSICIANS
\", \"CENTER NO. 2
\", \"CONDOMINIUM ASSOCIATION
\", \"2827 FORT MISSOULA ROAD
\", \"MISSOULA, MT 59804
\"} to «constant mAOHcent»." number -10006 from «class paln» of {"MISSOULA COMMUNITY PHYSICIANS
", "CENTER NO. 2
", "CONDOMINIUM ASSOCIATION
", "2827 FORT MISSOULA ROAD
", "MISSOULA, MT 59804
All I'm trying to do is center the text in a text frame if a condition is met, else left align it if another condition is met.
Any suggestions woudl be appreciated.

Answer 1

Don't get the lines first:
                              if (theTextPos = "B") then
                                        set justification of every line to left align
                              else
                                        set justification of every line to center align
                              end if