path_create doesnt work

var dist = 0;
	
	ENTITY* ball = ent_create("ball.mdl", vector(0,0,20),NULL);
	
	path_create(ball,4,4);
	
	var check = path_setnode(ball,1, vector(0,30,20),NULL);
	path_setnode(ball,2, vector(3*60,3*30,70),NULL);
	path_setnode(ball,3, vector(7*60,4*30,50),NULL);
	path_setnode(ball,4, vector(11*60,2*30,20),NULL);
	

	while(1){
	 	var node =	path_spline(ball,ball.x,dist);
	 
	 	dist += 5*time_step;
		DEBUG_VAR(check, 10);
		DEBUG_VAR(node,22);
	
		wait(1);
	}

function move_car()
 {
 	
 	ENTITY* car = ent_create("mini.mdl",0,0);
  	STRING* tpath;
 	path_set(road1.track_path,tpath);
 	printf(_chr(tpath));
 	ent_movepath(car,tpath, 5,2);
 	 	
}

STRING* tpath = str_create("#32");
// The rest of your code goes here...
ptr_remove(tpath);

printf("%s",tpath->chars);

path_set(ENTITY* entity,STRING* name)

A8.13 If an empty name string is given, the string is set to the path name the entity is currently attached to

STRING* tpath;
STRING* tpath = "#40";
STRING* tpath; = str_create("#40");

car = ent_create("mini.mdl",0,0);

	STRING* tpath ="";

// and = "#40" or = str_create("") or str_create("#40")

	

	path_set(road1.track_path,tpath);
 	ent_movepath(car,tpath, 5,2);
 	
 	ptr_remove(tpath);