WCF服务无法正确解析jsonP参数

I'm sending a call like so:

我发这样的电话:

$.ajax({
            url: myURL+functionName,
            contentType: "application/json; charset=utf-8", //also tried application/javascript
            cache: false,
            dataType: "jsonp",
            data: parameter,
            success:function(response){
                alert("great success!");
            },
            error:function(error) {alert("boo-urns");}
$.ajax