context of setTimeout and eval

setTimeout is a method of window object. "this" context refer to the window. But you can change its context in the following way. setTimeout does not support call method. setTimeout(function() { alert(this); }, 0); //window //setTimeout.call({}, function() { alert(this); }, 0); //not supported setTimeout((function() { alert(this); }).call({}), 0); //object eval is also a method of Global object, in the case of browse, this is window object. But is context defined by its Containing context. Eval also does not support call method function Foo() { this.TestContext = function() { eval("alert(this==window);"); //show false setTimeout(function() { alert(this == window); }, 0); //show true } } var f = new Foo(); f.TestContext(); eval("alert(this);"); eval.call({}, "alert(this);"); //firefox does not support this, but IE support, but it does not change context