The curves of your mesh must already exist in position in the drawing before you can create a surface.
Use the Surface wizard or select Curve mesh from the surface toolbar flyout.
Optionally name the surface for future reference.
Pick the Row curves with the mouse and pick button, or choose them in the list and click Plus.
If you pick them out of sequence, change the sequence with the Up and Down arrow buttons.
Pick the Column curves with the mouse and pick button, or choose them in the list and click Plus.
If you pick them out of sequence, change the sequence with the Up and Down arrow buttons.
Specify an acceptable Tolerance. This tolerance is used in approximating some of the curves.
Click Preview to view the surface.
Click Zero twists if you want the surface to be flatter.
Click Preview to see how the current settings affect the surface.
Click Finish or OK to create the surface.