Changing 2d features to 3d?

[SandySuy]

Hi,

I have 2d polylines which I would like to give 3d elevation data to.
I currently have a contour shapefile which is displaying correctly and would like these other polylines to gain its elevation points from these contours.

Is there any way I can go about getting this done?
I have attached an image to show you what I am working with.

Edit: I am trying to get the lines at the bottom to match up with the surface at the top.

[JakubSisak]

create a surface from the contours (or use the original surface the contours were created from) then convert 2D lines to 3D by interpolating shape. (version 10)

[SandySuy]

create a surface from the contours (or use the original surface the contours were created from) then convert 2D lines to 3D by interpolating shape. (version 10)

Thanks for the quick reply Jakub,

I am trying to use the Topo to Raster tool but it just gives me a slightly larger, flat, black surface which is at ground level. Tried changing the cell size to 1 instead of the default it gives me at 23 (which I think is too high) but it never finishes and hangs around on 100% then dropping back down to ~60% and starts counting up again to go back down again.

Any ideas?

[SandySuy]

Any way to skip the creation of a surface file? 😞