Some more doubts in postgresql -- Urgent

Hai everybody,
Thanks for Ur immediate reply, Jie Liang.
I had gone through the document plpgsql-porting.html, U mentioned already.
It was quite useful.
1) But, in that there is nothing about the Calling of plpgsql function(equivalent of Oracle stored procedure with many OUT parameters) from java code and returning of the plpgsql values corresponding to the Oracle OUT parameter, to the Java code, as this is my current issue to be solved urgently.
I want some answers related to this.

2) Moreover, somebody had said that OID in postgresql is the equivalent of Oracle's ROWNUM.
I cannot agree this, because Oracle's ROWNUM is table-specific, whereas postgresql OID is database specific.
Because of this difference, I'm unable to delete from tables based on ROWNUM, which I was asked to do.
Can anybody help me out to solve this issue, as quickly as possible?

3) What is the syntax for plpgsql GOTO label. When I use like this, I get some parse errors:
start:
.....
.....
....
GOTO start;
How to solve this issue? Can anybody point out, where I am going wrong?
4) My Oracle stored procedure which is to be converted to plpgsql function contains
EXIT WHEN SQL%ROWCOUNT = 0; TO COME OUT OF A LOOP.
How should it be converted in postgresql?

Since I'm in need of the answers very urgently, please send the answers as quickly as possible.

I'll be happy if I can get the answers by today or tomorrow.

Thanks everybody in advance.
Senthil