Are all compaq laptop chargers the same?

Ok, so my Compaq laptop charger broke and i need a new one. the laptop is not a newer one but it's not super old either. I have noooooo idea what year it is but taking a random guess, it's probably somewhere around 2007 or so? I'm looking at some on e-bay and i want to make sure before i buy it, it's the same charger.