By "lurch" do you mean that is seems to rev a bit then suddenly take a lurch forward, as if it were slipping a bit and then catching? I am also assuming you mean this is an automatic transmission. Also, is there any unusual noise before/as it does this?
Changing the fluid is certainly a good idea but if the problem persists or you are hearing whining noises as above, then it may need work. However, if it comes to that, try dumping a bottle of this in to it.
Molly Slip It's not a cure but can (depending on the issue) add tens of thousands of miles to the point where you eventually have to have the transmission repaired/replaced.
HOWEVER, as with all automotive problems, your best bet when you are not sure yourself is before trying any best intentioned advice, take it to a trusted mechanic who can take it for a drive and tell you what is realllly wrong.
