Javascript example

HTML

<button type="button" onclick="randomcard()"> Deal Card </button>
<br><h7 id="result"></h7>

JavaScript

var cardsInDeck = new Array();
cardsInDeck[0] = "Ace of spades";
cardsInDeck[1] = "ace of clubs";
cardsInDeck[2] = "ace of diamonds";
cardsInDeck[3] = "ace of hearts"
cardsInDeck[4] = "King of diamonds"

function randomcard(){
    var res = document.getElementById("result");
    res.innerHTML=cardsInDeck[Math.floor(Math.random()*cardsInDeck.length)];
}