12 in decimal is 1010
in Gray code.
example of convert binary number to gray code in javascript
<!-- Binary To Gray Code -->
<script type="text/javascript">
function binaryToGray (number){
if(isBinary(number)){
var gray = "";
gray = gray + number.charAt(0);
for (var i = 1; i < number.length; i++) {
if (number.charAt(i) == number.charAt(i-1)) {
gray = gray + '0';
}
else{
gray = gray + '1';
}
}
document.getElementById('result').innerHTML = gray;
}else{
document.getElementById('result').innerHTML = "Input is not a binary number";
}
}