The installer was unable to access the "smf" database. With some hosts, you have to create the database in your administration panel before SMF can use it. Some also add prefixes - like your username - to your database names.
can someone please help... :)
Do you have a database? If so, do you have the database server, database name, username and password necessary to access the database?
Make sure you create the database first - if SMF tries to create it and can't (many hosts have it set up so you have to create databases through your site's control panel), you'll get this error. If you entered the database info, make sure all the information you entered is correct and that the database actually exists.