marked ppp-object

Hi list,

that's probably an easy question but I couldn't get it right.
I want to coerce a SpatialPointsDataFrame to a marked ppp- object. But I don't
know how to attach the marks to the ppp-object.

C67mF_K<-readOGR (".", "C67mF_K")  #read shapefile that contains points for
cases and controls with one variable "typ"

str (C67mF_K)
Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots
  ..@ data       :'data.frame': 5968 obs. of  4 variables:
  .. ..$ ID     : num [1:5968] 4336 4106 994 325 3145 ...
  .. ..$ POINT_X: num [1:5968] 2576860 2574710 2576790 2575400 2575600 ...
  .. ..$ POINT_Y: num [1:5968] 5706080 5706060 5706230 5706210 5706310 ...
  .. ..$ typ    : Factor w/ 2 levels "F","K": 2 2 2 2 2 2 2 2 2 2 ...
  ..@ coords.nrs : num(0)
  ..@ coords     : num [1:5968, 1:2] 368483 366335 368420 367030 367234 ...
  .. ..- attr(*, "dimnames")=List of 2
  .. .. ..$ : NULL
  .. .. ..$ : chr [1:2] "coords.x1" "coords.x2"
  ..@ bbox       : num [1:2, 1:2] 322028 5705358 451515 5808359
  .. ..- attr(*, "dimnames")=List of 2
  .. .. ..$ : chr [1:2] "coords.x1" "coords.x2"
  .. .. ..$ : chr [1:2] "min" "max"
  ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots
  .. .. ..@ projargs: chr " +proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs"

ppC67mF_K<-as(C67mF_K, "ppp", marks = typ)

I get the error message: unused arguments:  (marks = typ)

I would grateful for any hint.

Dorothea