Any effort? This has been done so many times before and internet is full of such examples.
However, my first question would be if you are in control of the web service? If yes, I would rather remove the duplicate values on the web service method itself. It will give you an advantage that you will have similar behaviour across all consumers of your web service.
Otherwise, you could use the link below to start with:
http://manasbhardwaj.net/get-unique-values-from-a-javascript-array-using-jquery/
Disclaimer: Points to my own article.
function GetUnique(inputArray)
{
var outputArray = [];
for (var i = 0; i < inputArray.length; i++)
{
if ((jQuery.inArray(inputArray[i], outputArray)) == -1)
{
outputArray.push(inputArray[i]);
}
}
return outputArray;
}