SQL & PL/SQL :: Hierarchical Query To Display Chart Of Account?

I want Hierarical query to display my Chart_Of_Account. I want to make a tree Form in 6i error i am getting is connect by nocycle prior account_code=parent_code
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ERROR at line 4:
ORA-00920: invalid relational operator

Table

Create Table Chart_Of_Account (Account_Code Char(19), Account_Title varchar2(70), Parent_Code Char(19))
insert into Chart_Of_Account ('DGHOA01010101000001','TEST','DGHOA01010100000000')
insert into Chart_Of_Account ('DGHOA01010101000002','TEST1','DGHOA01010100000000')
insert into Chart_Of_Account ('DGHOA01010101000003','TEST2','DGHOA01010100000000')

select -1,level,account_code||' - '||ACCOUNT_Title,'NULL',to_char(ACCOUNT_CODE)
connect_by_iscycle from chart_of_account
start with Substr(account_code,13,7)='0000000'
connect by nocycle prior account_code=parent_code