Objects are not passed by reference but by value which is a reference (copy of reference)...
In your example you're not even passing an object but a primitive value type.
If you want a reference, then you need to wrap it in object element like:
var test = { val: true };
function changeThisBoolPlease(asd){
asd.val=!asd.val;
}
alert(test.val);
changeThisBoolPlease(test);
alert(test.val);