Ah.Finally all the problems except a very little one is fixed.
Now the player won't jump,stand,walk while below.He will only crawl.
The little problem is that.He can still jump a little(probably because of the short collision mask.While jumping,the crawling animation plays.So If you press the up arrow key repeatedly while below the platform,it seems like he is crawling.
Help me fix this please.And is there any way to shorten my events?