Carpentry and Woodworking - Anyone help a bird change some door handles please?

Hi,
i am helping my mum do some work to her bungalow built about 30 years ago by wimpy or similar. I am changing the door knobs but cannot replace them with some new ones. When i take the old ones off i am left withat least a 2 inch circular hole in the door as the old handles seem to be secured by screwing into each other with the metal bar rather than be secured to the door by use of screws through the circular plate into the door. This means that the new knobs which do have a circular plate and holes to affix them to the door have no wood to screw into as there is a large hole there.!
Can any one help me get some old style knobs or shall i just get new doors ?
Can any one help please
a bird x

Quick-set locks/knobs 2 3/8" don't screw into the wood. Why can't you use them?

Not that familiar with UK door latches. Maybe someone from there can comment or post a pic if you can.

Take a look at this web site it should help you. I think you just bought the wrong style door knobs, probably the type that are meant for mortised locks.

Replace a Doorknob - How to Install a Doorknob Video - About.com (http://video.about.com/homerepair/How-To-Replace-A-Doorknob.htm)