Click and move

Could someone give me a tutorial or code where you have an entity that the camera follows and rotates with, and you move along a terrain by using click-move. I know this is alot but I can't seem to make it work without glitches.

Show us what code you have.

graphics3d 800,600,32,2
camera=createcamera()
avatar=createcube()
terrain=loadterrain("your height map goes here")
;scale the terrain appropriately, I am sure you know how to do this...
entitypickmode terrain,2

;define startx#,startz# as some position on your terrain
positionentity avatar,startx#,terrainy(terrain,startx,0,startz),startz#

positionentity camera,entityx(avatar),entityy(avatar)+10,entityz(avatar)-10
pointentity camera,avatar
targetx#=startx
targetz#=startz

repeat

if mousehit(1)>0 then 

  if camerapick(camera,mousex(),mousey())>0 then 
     targetx#=pickedx()
     targetz#=pickedz()

 endif 


endif 

if sqr((targetx-startx)^2+(targetz-startz)^2)>1.0 then 
rotateentity avatar,0,vectoryaw(targetx-startx,0,targetz-startz),0
moveentity avatar,0,0,0.5 
positionentity avatar,entityx(avatar),terrainy(terrain,entityx(avatar),0,entityz(avatar)),entityz(avatar)
positionentity camera,entityx(avatar),entityy(avatar)+10,entityz(avatar)-10
pointentity camera,avatar
endif 
startx=entityx(avatar)
startz=entityz(avatar)


updateworld
renderworld
flip


until keydown(1)

There is some basic code to get you started

thanks