The X button

Im just about done with my program, im just doing a bit of error checking now, and in my program, i wanted to take out the X button and just allow the user to click OK to get out of the dialog box. I was wondering if you thought that was bad programming or not? I just wanted to do that so I wouldnt have to deal with changing a lot of the code, because if I keep the X button there, there would be a lot more code id have to add, and its not that i cant do it, i was just wondering if it is absolutely necessary to have the X button.