private static void removeFromGrid(){
		
		if(!negativeAmp.isEmpty()){
			
			int fromCol = 0;
			int fromRow = 0;
			int toCol = 0;
			int toRow = 0;
			
			for(int i=0; i<negativeAmp.size(); i++){
				
				//reset values after erbery iteration, so last value not carried over
				fromCol = 0;
				fromRow = 0;
				toCol = 0;
				toRow = 0;
				
				String[] values = negativeAmp.get(i).split(":");
				
				String column1 = values[0].substring(0,1);
				fromCol = convertLetterToNum(column1) - 1;
				
				if(values[0].length() == 3){
					
					fromRow = Integer.parseInt(values[0].substring(1,3)) - 1; 
				}
				else{
				
					fromRow = Integer.parseInt(values[0].substring(1,2)) - 1;
				}
				
				
				if(values.length > 1){
				
					String column2 = values[1].substring(0,1);
					toCol = convertLetterToNum(column2) - 1;
					
					if(values[1].length() == 3){
						
						toRow = Integer.parseInt(values[1].substring(1,3)) - 1; 
					}
					else{
					
						toRow = Integer.parseInt(values[1].substring(1,2)) - 1;
					}
				}
				
				if(toCol != 0){
				
					for(int j = fromRow; j <= toRow && j<10; j++){
						for(int k = fromCol; k <= toCol && k<10; k++){

							grid[j][k] = "-";	
						}
					}
				}
				else{
					
					grid[fromRow][fromCol] = "-";
				}
				
			}
			
				
		}
	}