Changing values of a script from another script not showing in game

The problem i am curently facing is that i am changing variables of a script from another script and i am not able to see those variables change in game.If i exit the game and start the game again i see them change but this should not happend.

here is my code:

      if(Exp >= 100)
	    {
		LevelUP = true;
		GameManager.Level ++;
		GameManager.SkillPoints ++;
        }

in the other script the level and skill points are just decleared as public and are shown in game via OnGUI so they are updated like they should.

See how to use static variables here :

static variables