Internet Explorer truncating flashVars containing JSON

Yep IE treats flashVars differently to all the other major browsers, I believe you need to make use of the JavaScript encodeURIComponent method which will escape all reserved characters from your String, eg:

// Removing all reserved characters from the flashVar value.var flashVars = {   myVar: encodeURIComponent('{"url":"http://google.com/", "id":"9999"}'),};

If you are passing multiple values in the flashVars then you could iterate through them and encode all chars in a single pass:

var flashVars = {   myVar: '{"url":"http://google.com/", "id":"9999"}',   anotherVar: 42};// Escape all values contained in the flashVars object.for (key in flashVars) {    if (flashVars.hasOwnProperty(key)) {        flashVars[key] = encodeURIComponent(flashVars[key]);    }}

As @dgmdan and @bcmoney suggested, it would probably make your code easier to read if you made use of JSON.stringify - however, you need to bear in mind that IE8 and below do not have a native JSON object, so you will need to include Crockford's JS Library in your HTML page.

// Making use of a JSON library.var flashVars = {   myVar: encodeURIComponent(JSON.stringify({ url: "http://google.com/", id: "9999"})),};

Also, it's worth bearing in mind that flashVars are limited to ~64k; so if you are planning to pass a lot of data, it might be better to use an ExternalInterface call to pull them from the JavaScript instead.

Try this to replace your first 3 lines:

var subVars = { url: "http://google.com/", id: "9999" };var flashVars = { myVar: JSON.stringify(subVars) };