i am kinda new to sql programing. just saying that to get it out of the way. i know how to connect to a database but i don't know how to check to see if a result is received from a select statement. this is my select statement

Code:
da.SelectCommand = New OleDbCommand("SELECT * FROM userinfo WHERE username =" & UsernameTextBox.Text)
i need to know if there is a user with that username and if there is then i will need to read the password for that person. then if both username and password are correct then i will show form 2. any help is welcome.