public void insertString(int offset,
            String str,
            AttributeSet a)
            throws BadLocationException{
		if(str.length() == 1 && str.charAt(0) == '\n' && offset>0){//New line
			String s=getText();
			//Locating previous line
			int lineStart=offset-1;
			for(; lineStart>=0; lineStart--)
				if(s.charAt(lineStart)== '\n') break;
			lineStart++;
			int added;
			for(added=0;lineStart+added<offset;added++){
				char c= s.charAt(lineStart+added);
				if(c != ' ' && c != '\t'){
					break;
				}
			}
			if(added >0){
				str += s.substring(lineStart,lineStart+added);
			}
		}
		super.insertString(offset, str,a);
	}