How do you make a platform move down when you stand on it and move up to it's original position when you don't stand on it?

When i have read things in these forums i have came across the term string. Apparently you can make a string as event and make actions for it. But how do you make one? I can't find it anywhere.

what do you mean by shooting in half a circle?

How many bullets?

Should the bullets shoot at the same time?

The turret should shoot in this ( movement. One bullet at a time. The bullet should shoot one by one. I know that you probably use some offsets whit the sine behavior and mix it whit the bullet behavior but what offsets?

I have a enemy that consist of the body and the arm. The body is it's own sprite and the arm is it's own sprite. Obviously so should i pin the arm to the body. This is where problems start. If i make the event on start of layout Arm Pin to Body position and angle it works for one version of the body sprite. If i make more then one copy of the body sprite the arm doesn't pin. And i want to have multiple copies of that enemy. Since the arm only seem to be able to pin to one copy of the body sprite i made multiple sprites of the body and the arm whit the same image and animation properties. So everywhere where a copy of the body sprite was located i placed a new body and arm sprite. I made every new arm pin to a new body. So far everything sounds well. But when i tried to run the game the problems came back. The arm sprites animation has 93 frames. And every frame has a image that takes relativly high amount of memory. The arm sprite takes up 100 MB. So for every new arm sprite i make 100 MB get's added to the project. Whit all arm sprites i need the project takes up so much memory that i can't run it anymore and i don't think alot of others would be able to either. So i can't create multiple versions of the arm sprite. So i erased all new arm sprites and only left the first one intact- My next solvation was to have multiple versions of the body and pin the first arm sprite to every single one of them. That doesn't work becuase if i pin the arm to one then one sprite the arm doesn't pin to any sprite. How am i going to solve this?. I want the arm to pin to the body and have multiple versions of the body and the arm. Why doesn't the arm pin if i make a copy of the body sprite. Why doesn't it do it?

I want my turret to try to be at the same altitude as the plyer by moving up and down. It should after 2 seconds stop moving and shoot.

http://postimg.org/image/ibevgazsn/

http://postimg.org/image/3ynqch4bv/¨

Here is my event sheets. The problem is that the the turret just moves to the ground and never shoot instead of moving up and down according to the player and shooting sometimes. Why does it do this?

I have different animations for jumping ducking and so forth. My problem is that when i try to duck after jumping the character doesn't duck directly and instead rotates in it's default animation. I can duck when i am walking just fine it's just when i am jumping it doesn't work. My character has a the rotate behavior. Here is the event sheets and the default, jumping and ducking animation.

http://postimg.org/image/3nlhkrded/

http://postimg.org/image/g1cxie6q5/

Default animation: http://postimg.org/image/cczao6d8v/

Jumping animation: http://postimg.org/image/v3lw7ss3n/

Ducking animation: http://postimg.org/image/keyzt2zcp/

I want you whit this information help me how i can make the character duck immediatly after jumping instead of rotating.

I have set my project to autosave every 20. The autosave is stored in a autosave file. Yesterday the power ran out while i was working on my project. I hadn't saved for a long time so when the power came back and i opened my project alot of things was gone since i hadn't saved in a while. But the autosave has all the data. The problem is when i try to open my autosave it says that the document is empty and error. There must be a way to use the autosave, what would be purpose for them existing otherwise?

I want a enemy to begin with moving diagonially downwards but after 3 seconds move diagoninally upwards. To do that you make the event simulate control up and simulate control left and thus the enemy moves diagonially downwards. Then you make a timer that last 3 seconds. Then you make a second 8 direction behavior. After 3 seconds have passed you make the first 8 direction disabled and make 8 direction2 simulate control up and simulate control left. If this worked rigth the enemy should begin by moving diagonially up and then move diagonially up. But instead it just moves diagonally down even after 3 seconds has passed. Why doesn't the timer work in this situation? If this isn't clear enough i will share my event sheet.

How do you make a sprite shoot the bullet sprite in a half circle. I mean a upwards half circle not a downwards half circle.

I want to create a turret that shoots three shots. One in 0 degrees, one in 45 degrees and one in 135 degrees. So i made the event every 2.0 seconds turret spawn shot 1 set angle of motion to 0 degrees and the same thing for the other two shots. But the turret just shots in one direction. I have no idea why it does this since it's such a clear thing. If this doesn't explain good enough i will show the event sheet.

The closest i have gotten is using the Custom behavior whit move towards angle but it doesn't work. I want to both know how a enemy that walks and a enemy that floats can do it.

When i mean following is that the enemy has it's usual movements but it will always be on screen. The enemy i am thinking of is a floating enemy. So i don't want to know how a enemy on ground would be able to follow you i want to know how a enemy that floats in the air follow you. Basically so should the enemy move whit the screen and adjust it's position to the player while still moving around. So how do you make this work?