Error about dbCreateParamInstByMasterName

Dear sir:

 I want to invoking a pcell in layout,and I write a code as follow:

     if(null(ddGetObj("Libname")) then libId=dbCreateLib("Libname") techSetTechLibName(libId "PDK_lib"))

     cellId=dbOpenCellViewByType("Libname" "test" "layout" "maskLayout" "w")

     dbCreateParamInstByMasterName(cellId "PDK_lib" "rppoly" "layout" get_pname(concat("list" "_" 1)) 0:0 "R0" 1
                list(
                     list("segW" "float" 10u)
                     list("segL" "float" 10u)
                    )
     )

     rodAlign(
              ?alignObj           rodGetObj(get_pname(concat("list" "_" 1)))
              ?alignHandle        'lowerLeft
              ?refPoint           list(0.0 0.0)
     )

But there are some warnnings: the cellview ID is not a voliad datebase ID.Can you help me?

 Thank you very much!