Why am I unable use GET to send parameters to WebMethod?

[DM]

My WebMethod looks like this:\[code\][WebMethod][ScriptMethod(ResponseFormat=ResponseFormat.Json, UseHttpGet=true)]public List<Person> HelloWorld(string hello){ List<Person> persons = new List<Person> { new Person("Sarfaraz", DateTime.Now), new Person("Nawaz", DateTime.Now), new Person("Manas", DateTime.Now) }; return persons;}\[/code\]And I'm trying to call this method using jQuery as:\[code\]$.ajax({ type: "GET", //have to use GET method cache: false, data: JSON.stringify(params), contentType: "application/json; charset=utf-8", dataType: 'json', url: "http://localhost:51519/CommentProviderService.asmx/HelloWorld", processData: true, success: onSuccess, error: onError //it gets called!});\[/code\]But it doesn't work. Instead of calling \[code\]onSuccess\[/code\] callback, it calls \[code\]onError\[/code\] in which I use \[code\]alert\[/code\] as:\[code\]alert(response.status + " | " + response.statusText + " | " + response.responseText + " | " + response.responseXML );\[/code\]which prints this:\[quote\] 500 | Internal Server Error | {"Message":"Invalid web service call, missing value for parameter: \u0027hello\u0027.","StackTrace":" at System.Web.Script.Services.WebServiceMethodData.CallMethod(Object target, IDictionary\[code\]2 parameters)\r\n at System.Web.Script.Services.WebServiceMethodData.CallMethodFromRawParams(Object target, IDictionary\[/code\]2 parameters)\r\n at System.Web.Script.Services.RestHandler.InvokeMethod(HttpContext context, WebServiceMethodData methodData, IDictionary`2 rawParams)\r\n at System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(HttpContext context, WebServiceMethodData methodData)","ExceptionType":"System.InvalidOperationException"} | undefined\[/quote\]I don't understand why I get this error. If I change the jQuery call to use \[code\]POST\[/code\] method and make \[code\]UseHttpGet=false\[/code\] , then it works great. But I want it to work with \[code\]GET\[/code\]. What needs to be fixed?