I am asking to input a letter. Then I should check if the letter is one of the letters in the prelist and then it is supposed to display some words

!== is not working for the letters 

```
<!DOCTYPE html>
<html>
<body>
<p>Type H/B/U:</p>

<input id="tipping" value="H" type="text"/>

<button onclick="myFunction()">Try it</button>

<p id="demo"></p>

<script>
function myFunction() {
  var b,r4;
  b= document.getElementById("tipping").value;
 if (b !=="H"||b !=="U" ||b !=="B") {
   r4="Du har ikke brukt stort bokstav eller tastet ugyldig tegn";
 } else if (b==="H"){
   r4="Hjemme";
 } else if (b==="U"){
   r4="Uavgjort";
 } else if(b==="B") {
   r4="Borte";
 }
   document.getElementById("demo").innerHTML = r4;
}
</script>

</body>
</html>

```

One is supposed to only type B,H,U. If B is typed then the message Borte is displayed and so on.. .