IE Home Page

Try as I might I cannot keep the home page as I set it up. Every time I close out IE and reopen it, it resets to http://www.solongas.com… and then to http://www.here4search.com. This search page lists sexually explicit search criteria which I do not want, particularly as my home page. How can I find where it is coming from and how do I delete it and permanently set my home page to that of my choice. Any suggestions?