Decompose a bitmask into bits

Introduction

I use bitmasks far less than I used to, but when I do use them I often have the need to decompose a value into its parts.

The BitDemaskerer

Enter a bitmask   Decimal Hexadecimal

This decomposes to: 0

The Code

Super simple:

<p>Enter a bitmask <input id="bitmask" onkeyup="GetBits()" style="width:100px;font-size:20px" type="text" />  
<input type="radio" id="Dec" name="outputFormat" value="dec" checked="true" onchange="GetBits()" /><label for="Dec">Decimal</label>
<input type="radio" id="Hex" name="outputFormat" value="hex" onchange="GetBits()" /><label for="Hex">Hexadecimal</label>
</p>

<p>This decomposes to: <span id="result">0</span></p>

<script type="text/javascript">
    function GetBits() {
		var hex = document.getElementById("Hex").checked;
        var elm = document.getElementById("bitmask");
        var value = parseInt(elm.value);
        if (isNaN(value))
            result.innerHTML = "Not a number";
        else {
            result.innerHTML = "";
            for (var i = 1; i <= value; i = i * 2)
                if ((value & i) > 0)
				{
					var bitRepresentation = hex? "0x" + i.toString(16) : i.toString();
                    result.innerHTML += (result.innerHTML == "" ? "" : ", ") + bitRepresentation;
				}
        }
    }
</script>