public int[] nucleobase(){
		//count the a's, c's, g's and t's, and highlighted the letters in different colors
		int[] count = new int[4]; //a, c, g, t
		for (int i=12; i<DNA_analyse.w.result.length()-14; ++i){
			if (DNA_analyse.w.result.charAt(i)=='<') { i+=3; continue; }
			switch (DNA_analyse.w.result.charAt(i)){
			case 'a': case 'A':
				++count[0];
				DNA_analyse.w.result = DNA_analyse.w.result.substring(0,i) 
					+ "<font color = #ff0000>" 
					+ DNA_analyse.w.result.substring(i,i+1) 
					+ "</font>" 
					+ DNA_analyse.w.result.substring(i+1,DNA_analyse.w.result.length());
				i+=28;
				break;
			case 'c': case 'C':
				++count[1];
				DNA_analyse.w.result = DNA_analyse.w.result.substring(0,i) 
					+ "<font color = #00ff00>" 
					+ DNA_analyse.w.result.substring(i,i+1) 
					+ "</font>" 
					+ DNA_analyse.w.result.substring(i+1,DNA_analyse.w.result.length());
				i+=28;
				break;
			case 'g': case 'G':
				++count[2];
				DNA_analyse.w.result = DNA_analyse.w.result.substring(0,i) 
					+ "<font color = #0000ff>" 
					+ DNA_analyse.w.result.substring(i,i+1) 
					+ "</font>" 
					+ DNA_analyse.w.result.substring(i+1,DNA_analyse.w.result.length());
				i+=28;				
				break;
			case 't':
				++count[3];
				break;
			}
		}
		return count;
	}