Hello All , I am building my Xcode(2.4) Carbon project using universal binaries. I have used HOpenDF call for opening file for reading. StringPtr voln; Str255 temp; c2pstrcpy (temp,lpszfname); pstrcat(voln, "\prj Dir:"); pstrcat(voln, temp); Err =HOpenDF (0,0,voln,fsRdPerm, &FileRefNo); It works on mac OS 10.4 but for mac OS 10.5 this api returns error code. Which is the suitable function call which will work on both OS 10.4 as well as 10.5. Or whether I need to have Xcode 2.5 version . Please Reply. Thanks & Regards , Pallavi.