I'm not sure what you mean by "In the parameter window". When you invoke a worklight adapter from the worklight studio, the parameter window that comes up is so that you can pass parameters to your adapter function, not REST parameters.
function getFeeds(myParameter) {
// myParameter is what is passed from the parameter window
WL.Logger.debug("inside method");
var input = {
method : 'get',
returnedContentType : 'json',
path : "ios/ClientadID.php"
};
If you're trying to pass a parameter for a GET or POST request, then you need to change your adapter "input" object like this:
function getFeeds() {
WL.Logger.debug("inside method");
var input = {
method : 'get',
returnedContentType : 'json',
path : "ios/ClientadID.php",
parameters: {"ad_id": 1}
};