Create A JSON Request

Create A JSON Request

Hi all!
I need to use postUrl function with JSON request parameter like this:
  2. {
  3.        "kind": "fusiontables#styleSetting",
  4.        "tableId": "TableID",
  5.        "styleId": 1,
  6.        "markerOptions": {
  7.               "iconName": "small_yellow"
  8.              },
  9.        "polylineOptions": {
  10.               "strokeColor": "#ff0000",
  11.               "strokeOpacity": 0.5,
  12.               "strokeWeight": 2
  13.              },
  14.        "polygonOptions": {
  15.               "strokeColor": "#666666",
  16.               "strokeOpacity": 1,
  17.               "strokeWeight": 1,
  18.               "fillColorStyler": {
  19.                      "kind": "fusiontables#gradient",
  20.                      "columnName": "TotalMedia",
  21.                      "gradient": {
  22.                             "min": 0,
  23.                             "max": 300,
  24.                             "colors": [
  25.                                    {
  26.                                           "color": "#ff0000",
  27.                                           "opacity": 0.5
  28.                                    },
  29.                                    {
  30.                                           "color": "#0000ff",
  31.                                           "opacity": 0.5
  32.                                    }
  33.                             ]
  34.                      }
  35.               }
  36.        }
  37. }

I'm compose following function:
  2. Colors = List();
  3. Color1 = Map();
  4. Color1.put("color","#ff0000");
  5. Color1.put("opacity", 0.5);
  6. Colors.add(Color1);
  7. Color2 = Map();
  8. Color2.put("color","#0000ff");
  9. Color2.put("opacity", 0.5);
  10. Colors.add(Color2);
  11. Gradient = Map();
  12. Gradient.put("min", 0.0);
  13. Gradient.put("max", 300);
  14. Gradient.put("colors",Colors);
  17. fillColorStyler = Map();
  18. fillColorStyler.put("kind","fusiontables#gradient");
  19. fillColorStyler.put("columnName","TotalMedia");
  20. fillColorStyler.put("gradient",Gradient);
  22. polygonOptions = Map();
  23. polygonOptions.put("strokeColor","#666666");
  24. polygonOptions.put("strokeOpacity",1.0);
  25. polygonOptions.put("strokeWeight",1);
  26. polygonOptions.put("fillColorStyler",fillColorStyler);
  28. markerOptions = Map();
  29. markerOptions.put("iconName","small_yellow");
  31. polylineOptions = Map();
  32. polylineOptions.put("strokeColor","#ff0000");
  33. polylineOptions.put("strokeOpacity",0.5);
  34. polylineOptions.put("strokeWeight",2);
  36. styleSetting = Map();
  37. styleSetting.put("kind","fusiontables#styleSetting");
  38. styleSetting.put("tableId",TableID);
  39. styleSetting.put("styleId",Style);
  40. styleSetting.put("markerOptions",markerOptions);
  41. styleSetting.put("polylineOptions",polylineOptions);
  42. styleSetting.put("polygonOptions",polygonOptions);
  44. info styleSetting;

The result is 
{"styleId":1,"tableId":"XXXXXXXXXXX","polygonOptions":"{fillColorStyler={columnName=TotalMedia, kind=fusiontables#gradient, gradient={min=0.0, max=300, colors=[{color=#ff0000, opacity=0.5}, {color=#0000ff, opacity=0.5}]}}, strokeColor=#666666, strokeWeight=1, strokeOpacity=1.0}","polylineOptions": " {strokeColor=#ff0000, strokeWeight=2, strokeOpacity=0.5} " ,"markerOptions": " {iconName=small_yellow} " ,"kind":"fusiontables#styleSetting"}

There are no quote inside  curly bracket and unnecessary outside ...
Google reject this JSON.

Anybody know how to solve this problem?