public Object getValueAt(int rowIndex, int columnIndex) {
		Assignment as = assignments.get(rowIndex);
		switch(columnIndex){
		case 0: 
			return as.getName();
		case 1: 
			return as.getType();
		case 2:
			return as.getGradedPoints();
		case 3:
			return as.getTotalPoints();
		case 4: 
			return as.getDescription();
		case 5: 
			return as.getGroupId();
		case 6:
			return as.getStudentId();
		case 7:
			return as.getAssignmentId();
		case 8:
			return as.getAssignmentNumber();
		}
		return "";
	}