i set the gravity by adding -2 at the c_move instruction and it works fine. the problem is when i do "if(key...) my.z +..."
the player keeps going upwards till i release the key, and if i use "on_key... = jump" it jumps but it doesnt wait until the player touches the floor, and i want it to be able to jump only when its on the floor, not when its in the air.