<script>
Function.prototype.$bind=function(object)
{
var callback = function () {
   return arguments[0];
}
with(object)
{
   return eval('callback(' + this.toString() + ')');
}
}

var obj={a:1,b:2};
var f=function (){
a=10;
b=11;
}.$bind(obj);

f();
alert(obj.a);
</script>