I have an entity wich can move up and down with the tilt move by using 2 different keys. The problem is that I want to move the entity with one key. This is the code for the movement of the entity.

Code:

---

my.skill15 = max(my.skill15,-15);
		my.skill15 = min(my.skill15,0);
		
		if(key_e == 1) 
		{
			my.skill15 -= 0.5*time_step;
		}
		if(key_d == 1)
		{
			my.skill15 += 0.5*time_step;	
		}
		
		ent_animate(my,NULL,0,0);
		ent_bonerotate(my,"arm_axis",vector(0,my.skill15,0));

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You see that the keys e and d are used to move the entity. But I want to move the entity by only using the e button, so it is moving up and down.

Is there a way to do something like that?