It is not a big discoverable problem for English development, AS1/2 escape() and AS3 escape() return the same result, but in double-byte characters, AS3 escape() now return the same format as JavaScript, if you want the old AS1/2 format, you have to use encodeURI() or encodeURIComponent().

ActionScript 1/2

var a:String = "香港:";
trace(escape(a));  // %E9%A6%99%E6%B8%AF%3A

ActionScript 3

var a:String = "香港:";
trace(escape(a));   // %u9999%u6E2F%3A
trace(encodeURI(a)); // %E9%A6%99%E6%B8%AF:
trace(encodeURIComponent(a)); // %E9%A6%99%E6%B8%AF%3A

JavaScript

var a = "香港:";
alert(escape(a));  // %u9999%u6E2F%3A
alert(encodeURI(a)); // %E9%A6%99%E6%B8%AF:
alert(encodeURIComponent(a)); // %E9%A6%99%E6%B8%AF%3A