var pics_f=new Array(25)
     pics_f[0]="bmp/lum/squares_f/01_f.jpg";
     pics_f[1]="bmp/lum/squares_f/02_f.jpg";
     pics_f[2]="bmp/lum/squares_f/03_f.jpg";   
     pics_f[3]="bmp/lum/squares_f/04_f.jpg";
     pics_f[4]="bmp/lum/squares_f/05_f.jpg";
     pics_f[5]="bmp/lum/squares_f/06_f.jpg";
     pics_f[6]="bmp/lum/squares_f/07_f.jpg";
     pics_f[7]="bmp/lum/squares_f/08_f.jpg";   
     pics_f[8]="bmp/lum/squares_f/09_f.jpg";
     pics_f[9]="bmp/lum/squares_f/10_f.jpg";
     pics_f[10]="bmp/lum/squares_f/11_f.jpg";
     pics_f[11]="bmp/lum/squares_f/12_f.jpg";
     pics_f[12]="bmp/lum/squares_f/13_f.jpg";   
     pics_f[13]="bmp/lum/squares_f/14_f.jpg";
     pics_f[14]="bmp/lum/squares_f/15_f.jpg";
     pics_f[15]="bmp/lum/squares_f/16_f.jpg";
     pics_f[16]="bmp/lum/squares_f/17_f.jpg";
     pics_f[17]="bmp/lum/squares_f/18_f.jpg";   
     pics_f[18]="bmp/lum/squares_f/19_f.jpg";
     pics_f[19]="bmp/lum/squares_f/20_f.jpg";
     pics_f[20]="bmp/lum/squares_f/21_f.jpg";
     pics_f[21]="bmp/lum/squares_f/22_f.jpg";
     pics_f[22]="bmp/lum/squares_f/23_f.jpg";   
     pics_f[23]="bmp/lum/squares_f/24_f.jpg";
     pics_f[24]="bmp/lum/squares_f/25_f.jpg";

    var pics_d=new Array(25)
     pics_d[0]="bmp/lum/squares_d/01_d.jpg";
     pics_d[1]="bmp/lum/squares_d/02_d.jpg";
     pics_d[2]="bmp/lum/squares_d/03_d.jpg";   
     pics_d[3]="bmp/lum/squares_d/04_d.jpg";
     pics_d[4]="bmp/lum/squares_d/05_d.jpg";
     pics_d[5]="bmp/lum/squares_d/06_d.jpg";
     pics_d[6]="bmp/lum/squares_d/07_d.jpg";
     pics_d[7]="bmp/lum/squares_d/08_d.jpg";   
     pics_d[8]="bmp/lum/squares_d/09_d.jpg";
     pics_d[9]="bmp/lum/squares_d/10_d.jpg";
     pics_d[10]="bmp/lum/squares_d/11_d.jpg";
     pics_d[11]="bmp/lum/squares_d/12_d.jpg";
     pics_d[12]="bmp/lum/squares_d/13_d.jpg";   
     pics_d[13]="bmp/lum/squares_d/14_d.jpg";
     pics_d[14]="bmp/lum/squares_d/15_d.jpg";
     pics_d[15]="bmp/lum/squares_d/16_d.jpg";
     pics_d[16]="bmp/lum/squares_d/17_d.jpg";
     pics_d[17]="bmp/lum/squares_d/18_d.jpg";   
     pics_d[18]="bmp/lum/squares_d/19_d.jpg";
     pics_d[19]="bmp/lum/squares_d/20_d.jpg";
     pics_d[20]="bmp/lum/squares_d/21_d.jpg";
     pics_d[21]="bmp/lum/squares_d/22_d.jpg";
     pics_d[22]="bmp/lum/squares_d/23_d.jpg";   
     pics_d[23]="bmp/lum/squares_d/24_d.jpg";
     pics_d[24]="bmp/lum/squares_d/25_d.jpg";

	function get_random(n)
	{// get a random number [0;n]
		return Math.round(Math.random()*n);
	}

	function swap(i_id)
	{
		//c_i = document.getElementById("p_"+i_id);
		//c_i.firstChild.setAttribute('src',pics_f[get_random(24)]);
		i_id.setAttribute('src',pics_f[i_id.id]);
		for (i=0; i<2; i++){
			a=get_random(36); if (a==0) a=1;
			i_id = document.getElementById("p_"+a);
			i_id.firstChild.setAttribute('src',pics_f[get_random(24)]);
			a=get_random(36); if (a==0) a=1;
			i_id = document.getElementById("p_"+a);
			i_id.firstChild.setAttribute('src',pics_d[get_random(24)]);
		}
		return false;
	}

	function deswap(i_id)
	{
		//c_i = document.getElementById("p_"+i_id);
		//c_i.firstChild.setAttribute('src',pics_d[get_random(24)]);
		b = get_random(24);
		i_id.setAttribute('src',pics_d[b]);
		i_id.setAttribute('id',b);
		return false;
	}

	function initial_config()
	{
		for (i=1; i<=36; i++) {
				c_p = document.getElementById("p_"+i);
				c_p.innerHTML = "";
				imag = document.createElement("img");
				a = get_random(24);
				imag.setAttribute("src", pics_d[a]);
				imag.setAttribute("id", ""+a);
				imag.onmouseover = function() { swap(this) };
				imag.onmouseout = function() { deswap(this) };
				c_p.appendChild(imag);
			}
		return false;
	}