function schwerkraft()
{
	
	var abstand[3];
	vec_set(abstand,my.x);
	abstand[2] -= 5;
	if(c_trace(my.x,abstand,IGNORE_PASSABLE|USE_BOX|IGNORE_ME) == 0)
	{
		//		beep();
		
		if(my.Z_MOVE > -50)
		{
			my.Z_MOVE = -2;
		}
	}
	else
	{
		my.Z_MOVE = 0;
		
			
	}
	
}

#define speed_z skill50
var key_space_off = 0;
VECTOR temp;
...
vec_set(temp,vector(my.x,my.y,my.z-500));
c_trace(my.x,temp,IGNORE_ME | IGNORE_PASSABLE);
if(!trace_hit) vec_set(target,temp);

if(my.z+my.min_z+5 > target.z || my.speed_z > 0)
{
	my.speed_z = maxv(my.speed_z-10*time_step,-80);
	c_move(me,nullvector,vector(0,0,my.speed_z*time_step),IGNORE_PASSABLE | GLIDE);
}
else
{
	my.speed_z = 0;
	my.z += (target.z-my.min_z+3-my.z)*time_step; //or set the position directly... (3 and 5 act as a simple buffer)
	if(key_space)
	{
		if(key_space_off)
		{
			my.speed_z = 50;
			key_space_off = 0;
		}
	}
	else key_space_off = 1;
}

#define speed_z skill50
var key_space_off = 0;
VECTOR temp;

action act_player()
{
	c_setminmax(my);
	my.min_z += 40;
	while(1)
	{
		my.x += (key_w-key_s)*5*time_step;
		my.y += (key_a-key_d)*5*time_step;
		vec_set(temp,vector(my.x,my.y,my.z-500));
		c_trace(my.x,temp,IGNORE_ME | IGNORE_PASSABLE);
		if(!trace_hit) vec_set(target,temp);

		var target_height = target.z-my.min_z+40;

		if(my.z > target_height+5 || my.speed_z > 0)
		{
			my.speed_z = maxv(my.speed_z-10*time_step,-80);
			c_move(me,nullvector,vector(0,0,my.speed_z*time_step),IGNORE_PASSABLE);
		}
		else
		{
			my.speed_z = 0;
			if(my.z > target_height) my.z += (target_height-my.z)*time_step;
			else my.z = target_height;
			if(key_space)
			{
				if(key_space_off)
				{
					my.speed_z = 50;
					key_space_off = 0;
				}
			}
			else key_space_off = 1;
		}
		wait(1);
	}
}