public void keyPressed(int key, char c){
		// same code as the mouseclicked method, except that this is triggered by keyboard buttons
		// KEY_1 toggles building rocket tower
		// KEY_2 toggles building maching gun tower
		// KEY_3 toggles building slow tower
		if(key == Input.KEY_1){
			if(buildR){
				this.RTBimage = this.rocket;
				this.buildR = false;
				this.gameState.currentState = GameplayState.GameState.NORMAL;
			}
			else{
				this.RTBimage = this.cancel;
				this.STBimage = this.slow;
				this.MGBimage = this.mgun;
				this.buildS = false;
				this.buildM = false;
				this.buildR = true;
				this.gameState.currentState = GameplayState.GameState.PLACE;
			}
		}
		else if(key == Input.KEY_2){
			if(buildM){
				this.MGBimage = this.mgun;
				this.buildM = false;
				this.gameState.currentState = GameplayState.GameState.NORMAL;
			}
			else{
				this.MGBimage = this.cancel;
				this.STBimage = this.slow;
				this.RTBimage = this.rocket;
				this.buildS = false;
				this.buildR = false;
				this.buildM = true;
				this.gameState.currentState = GameplayState.GameState.PLACE;
			}
		}
		else if(key == Input.KEY_3){
			if(buildS){
				this.STBimage = this.slow;
				this.buildS = false;
				this.gameState.currentState = GameplayState.GameState.NORMAL;
			}
			else{
				this.STBimage = this.cancel;
				this.MGBimage = this.mgun;
				this.RTBimage = this.rocket;
				this.buildS = true;
				this.buildR = false;
				this.buildM = false;
				this.gameState.currentState = GameplayState.GameState.PLACE;
			}
		}
	}