Trouble making module

[shivanth m p <fordearlinux@xxxxxxxxx>]

I created a kernel module for the 2.6.33 kernel outside the kernel source directory . When i give the make command it says

Nothing to be done for /root/mydrivers

Here's my makefile 
               
 obj-m +=mydiver.o
modules :
             make -C ..kerndev/linux-2.6/  M=$(PWD) modules
clean : 
             make -C ../kerndev/linux-2.6/  M=$(PWD) clean

my module source is in /root/mydrivers and the kernel source in /root/kerndev/linux-2.6