Problem with CUDA PTX function calls

Hi,
I am facing one problem in PTX file exection.
I am not able to call a function from inside an entry defined at the top of entry…
something like this…
… register declarations etc…
.func abc
{
…code…
ret;
}
.entry def
{
… code…
call abc;
…code…
exit;
}
although wrting function inline is working can anybody help me in this regard …
whether this feature is not implemented … or i am wrong somewhere…
or there is any other method of calling functions…
Pls reply soon…