You can user browser native function JSON.stringify to do this

var foo = {};
foo.bar = "new property";
foo.baz = 3;

var jsonString = JSON.stringify(foo);

https://developer.mozilla.org/En/Using_JSON_in_Firefox

And IE8 also supports it - http://blogs.msdn.com/b/ie/archive/2008/09/10/native-json-in-ie8.aspx

If you pass html content in the template variables, you have to use format to make sure that the html content gets converted into real html elements.

See this Stack overflow post http://stackoverflow.com/questions/4570222/htmlentities-equivalent-in-jquery-template-plugin

And this documentation - http://api.jquery.com/template-tag-html/

Here is a Stack overflow post with javascript regex solution for this problem.

http://stackoverflow.com/questions/1353408/messageformat-in-javascript-parameters-in-localized-ui-strings

If you need to center a div within another div, here is the solution from Stack overflow post -

http://stackoverflow.com/questions/114543/how-to-center-div-in-div

Quoting example from the post below for quick reference,

<div id="outer">
  <div id="inner">Foo foo</div>
</div>

#inner {
  width: 50%;
  margin: 0 auto;
}

http://www.hccp.org/java-net-cookie-how-to.html

Same way you can set other headers like Content-Type, Accept to the HTTP request using the setRequestProperty method of URLConnection