The problem is in the way that you're creating the xmlHttp object. First you create an instance of XMLHttpRequest, then you try and use ActiveX which overwrites the already created object. That means, if the ActiveX object isn't available the xmlHttp object is rendered useless (as you know). You'll need to re-order/structure where you assign the new instance of whatever to xmlHttp such that you only try to use the IE approaches if 'new XMLHttpRequest' failed.