I have installed Postgresql 9.2 from graphical installer in Ubuntu 13.10 and Install PostGIS 2.0.3 through StackBuilder. All things went smooth. But it is not possible to create PostGIS database as there is no extension present in Extension. As far I know two more extension is needed to be there named 'postgis' and 'postgis_topology'. I have tried
CREATE EXTENSION postgis
but it returns there is no postgis.control file within the extension folder. What should I do now?