OpenWGA 7.10 - TMLScript reference

callback:

An optional JS-Function to read the response. The callback is called with an HttpResult object as parameter.

HTTP Status Code

// a simple get request
var result = WGA.HttpClient("http://some-domain.com").get(function(result){
    if(result.status==200)
    	console.log("result is", result.text);
    else console.error("HTTP Error", result.status)
})