vX Ajax is almost 10 bytes smaller

Okay, so 0 = false, so it makes sense that !0 = true. but also 1 = true, so that saved 1 byte.

Since there’s no .readyState attribute > 4, instead of .readyState == 4, you can do .readyState>3

the big one was ActiveX, which was originally

x=new(this.ActiveXObject?ActiveXObject:XMLHttpRequest)('Microsoft.XMLHTTP')

I noticed how this.activeXObject was repeated unnecessarily. So i added a new variable y

y=this.ActiveXObject

then I did:

y=this.ActiveXObject;x=new(y?y:XMLHttpRequest)('Microsoft.XMLHTTP')

thanks to dynamic languages, I could use x, and just reset it to something else (saving a variable declaration!)

x=this.ActiveXObject;x=new(x?x:XMLHttpRequest)('Microsoft.XMLHTTP')

Now I just need to find a way to shrink x.setRequestHeader('Content-type','application/x-www-form-urlencoded')