Edit in JSFiddle

var generate = function () {
    // Clear the output
    document.getElementById("RandomValue").value = '';
    // This is an integer-based TypedArray. It's values will be overridden
    var array = new Uint32Array(5);
    // Generate the requested number of cryptographically random values
    window.crypto.getRandomValues(array);
    // Loop over our array of pseudo-random numbers and append them to the output
    for (var i = 0; i < array.length; i++)
    document.getElementById("RandomValue").value = document.getElementById("RandomValue").value + "\n" + array[i];
}

<textarea id="RandomValue"></textarea>
<br />
<button type="button" onclick="generate()">Generate Random Numbers</button>

#RandomValue {
    width:400px;
    height:200px;
}