Error: String or binary data would be truncated. The statement has been terminated

[AdamSmith]

I'm trying to create a simple registration form, where data from textboxes etc. are input into a table called \[code\]users\[/code\]:\[code\]user_id intusername nchar(20)password nchar(20)... more columns\[/code\]Code:\[code\]Dim Username As String = txtUsername.ToString... more variable declarationslblDOB.Text = DOB.ToStringlblDOB.Visible = TrueDim ProjectManager As String = "test"... more constant declarationsDim conn As New SqlConnection("...conn string...")sqlComm = "INSERT INTO users(Username, Password, ...other columns...)" + "VALUES(@p1, @p2, ...other params...)"conn.Open()registerSQL = New SqlCommand(sqlComm, conn)registerSQL.Parameters.AddWithValue("@p1", Username)... other AddWithValuesregisterSQL.ExecuteNonQuery()\[/code\]I'm getting this error message:\[quote\] String or binary data would be truncated. The statement has been terminated.\[/quote\]