Delete Row Error

ok i have this simple delete statement which i cannot execute.... 
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim strdb As String = "Data Source=.SQLEXPRESS;AttachDbFilena....."
        Dim selkta As String = "DELETE FROM exams WHERE name = Allen"
        Dim conDB As SqlConnection
        Dim cmdDB As SqlCommand
  
        conDB = New SqlClient.SqlConnection(strdb)
        cmdDB = New SqlClient.SqlCommand(selkta, conDB)
     
        conDB.Open()
        cmdDB1.ExecuteNonQuery()
        conDB.Close()

    End Sub
it shows an error INVALID COLUMN NAME 'ALLEN' 
when  i write like this 'allen '
  DELETE FROM exams WHERE name =' Allen' "
then i get error  "The data types text and varchar are incompatible in the equal to operator"
what is the correct syntax ?....