Help with JDBC Exception java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver

I load the properties like this:
 
	private DBProperties initDBProperties(DBProperties dbp, ServletConfig c)
	{
		dbp.setDriver( c.getInitParameter("Driver") );
		dbp.setUrl(  c.getInitParameter("URL") );
		dbp.setUsername(  c.getInitParameter("User") );
		dbp.setPassword(  c.getInitParameter("Password") );
		dbp.setDBName(  c.getInitParameter("DatabaseName") );
 
		return dbp;
	}
 
and connect like this calling setDBProps from the servlet init method:
 
            private void initConnection()
            {
				String driver = dbprops.getDriver();
				String url = dbprops.getUrl();
				String username = dbprops.getUsername();
				String password = dbprops.getPassword();
 
                        try {
                                    Class.forName( driver );
                                    sqlConnection = DriverManager.getConnection( url, username, password );
                                    dbMetaData = sqlConnection.getMetaData();
                                    sqlConnection.close();
                                    
                        } catch (ClassNotFoundException e) {
                                    e.printStackTrace();
                        } catch (SQLException e) {
                                    e.printStackTrace();
                        }
            }
            
			
			public void setDBProps( DBProperties d)
			{
				dbprops = d;
				initConnection();
			}