onChange not firing for lookup no match - CRM 2013

Hi,

I am using CRM 2013, when entering a value into a lookup the onChange event is fired on tab off or click away if a single match is found. In fact with tab off it is fired twice!

But for no match or multiple match the onchange event is only fired when I tab away, it does not fire if you click off.

Is there a way of forcing the onChange to fire regardless of how the user chooses to leave the field and regardless of whether a matching record is available or not.

Thanks