i have two meshes , one is the circle and the other one is the cricle made of circles , i want to join these two , but if i just join them , when i tab in the meshes are independent , i want that where them vertex intersect a new vertex is created joing them.
i tried booleans and it gave me error , the meshes are just unfilled circles.
How?
Blender is not going to cut those edges automatically. You’ll have to do it by hand. You might use subdivide on the intersecting edges, then move the new vertices to the actual intersection, then merge them. That’s the hard way.
The easier way would be to make a section of the mesh you want, then spin dup it around the center, then remove doubles.
The Geom Tool script will cut the edges and create a vertex on the intersect of the two edges.
Once you have combined the meshes, in Edit Mode, select all. Open a script window and click Scripts>Mesh>Geom Tool, select Intersect: edge/edge (Cut). You might need to remove doubles afterwards.
boolean doesn’t work with meshes that aren’t closed
you will need to do what robbur has suggested 
Is this Geom tool in v2.45? I couldn’t see it in the “Mesh” menu item in the Scripts window.
It’s loaded on my machine, but that may be carried over from an older version.
The script and details can be found here:
http://www.hybird.org/~guiea_7/
wow thats hot !!!