Data Type Varchar And Text

I encounter this particular error.

Exception Details: System.Data.SqlClient.SqlException: The data types varchar and text are incompatible in the equal to operator.


Line 21:             Dim reader As SqlDataReader = command.ExecuteReader() 

This is the first time I'm trying out with MS SQL so I'm abit lost. I hope my code is correct and I've did a little search. I did not set "Text" in my database, I use int and varchar. Here's the affected part of my code and the database. Dim password As String = ""
Dim querystring As String = "SELECT Password FROM Member WHERE Username = @username"

'Dim conn as SqlConnection
Using conn As New SqlConnection(ConfigurationManager.ConnectionStrings("mainconnect").ConnectionString)
Dim command As New SqlCommand(querystring, conn)
command.Parameters.Add("@username", SqlDbType.Text)
command.Parameters("@username").Value = txtLogin.Text
conn.Open()

Dim reader As SqlDataReader = command.ExecuteReader()
While reader.Read()
password = reader("Password").ToString()
End While

reader.Close()

End Using

 

My database:

User_ID int(4)

Username varchar(50)

Password varchar(255)

Email varchar(50)

 

Any ideas?