Doubts on DATASET OPEN statments

Hi,

I have one question. In one program the statement

OPEN DATASET filename IN TEXT MODE FOR INPUT ENCODING DEFAULT.

is using to open the file. with out closing the file and one statement

OPEN DATASET filename IN TEXT MODE FOR INPUT ENCODING DEFAULT

is again opening the same file and it is giving the error "DATASET reopen".

But before the unicode conversion the code was running fine after the system to unicode environment it is giving error.

So my question is : can we use two open statement on one file with out closing the first open statement on the file in UNICODE environment.

can u please help me.

Thanks,

Venkatesh.