vec_for_vertex problem

entity* zug;

action pp_bol {
   var zz;
   zz = my.z;
   zug = my;
   
   while(1) {
      my.z = zz+9.6-hubring*-14-10;
      my.pan = molen.pan+100;     
      my.tilt = 26*hubring*sin(exzenter_pos+molen.pan);
      my.roll = 26*hubring*cos(exzenter_pos+molen.pan); 
            
      wait(1);
   }
}

function stange1() {
	var zpos1[3];
	var zpos2[3];
   vec_set(my.scale_x,vector(1.200,0.800,0.800));
proc_late();
   
   while(1) {
      
      vec_for_vertex(my.x,you,87);
      vec_for_vertex(zpos2.x,you,87);
      
      vec_for_vertex(zpos1.x,zug,41);
      vec_for_vertex(zpos2.x,zug,41);
      
      vec_lerp(temp.x,zpos1.x,zpos2.x,0.0);
      vec_diff(temp.x,temp.x,my.x);
      vec_to_angle(my.pan,temp.x);
      
      wait(1);
   }
}

   while(1) 
   {
      if((me!=0)&&(you!=0)&&(zug!=0)) 
      {
         vec_for_vertex(my.x,you,87);
         vec_for_vertex(zpos2.x,you,87);
      
         vec_for_vertex(zpos1.x,zug,41);
         vec_for_vertex(zpos2.x,zug,41);
      
         vec_lerp(temp.x,zpos1.x,zpos2.x,0.0);
         vec_diff(temp.x,temp.x,my.x);
         vec_to_angle(my.pan,temp.x);
      }
      wait(1);
   }