code: public int getAligSeq(Point point) {
  
  		for (int pos=0; pos<alignmentSize; pos++){
  			int i = getSeqPos(pos, point);
  			Point t = getPanelPos(pos,i);
  
  			if ( Math.abs(t.x - point.x) <= DEFAULT_CHAR_SIZE &&
  					Math.abs(t.y-point.y) < DEFAULT_CHAR_SIZE ) return pos;
  		}
  		return -1;
  	}
docs: Returns the index of the structure, for a given point in the Panel.
  Returns -1 if not over a position in the sequence alignment.
  @param point x and y coordinates in the panel
  @return which structure a point on the panel corresponds to