I want to convert a running joomla 1.0 based website into joomla 1.5 based site.
For design i will choose any good 1.5 template but How i can import 1.0 databse into 1.5 site's databse. my new joomla 1.5 site will have different url than old 1.0 joomla site.
I want to convert whole things of old 1.0 site to 1.5 site
The question is, how many extension, components, plugins are you using and is your joomla install clean or hacked? The Joomla Documentations have step by step guidelines on how to migrate from 1.0 to 1.5 and there even is a migration manager/helper.
If you have a non-hacked version, you should follow these instructions:
If you have a hacked version and an upgrade doesn't work (try it), then you will have to write your own migration scripts.