will it work?

Other day, my dad's dell monitor was out, due to white blank, so I put my IBM montior to hook up with Dell tower to see if it's working, if so, then we would know his dell montiior is broke. So I use my IBM monitor. It was working at first like when we can see the window Xp loading....then start blank again. I thought it was tower till my dad called and got new montior and it was working well with his dell tower which we found out his old dell montior broke. I was going to order new dell tower only, not with new dell montior, but would it work dell tower with my IBM montior? Please respond so I could order today. Thanks!