img=new Array()

img[100]="images/a_01.gif" 
img[101]="images/b_01.gif" 
img[102]="images/c_01.gif" 
img[103]="images/d_01.gif" 
img[104]="images/e_01.gif" 
img[105]="images/f_01.gif" 
img[106]="images/g_01.gif" 
img[107]="images/h_01.gif" 
img[108]="images/i_01.gif" 
img[109]="images/j_01.gif" 
img[110]="images/k_01.gif" 
img[111]="images/l_01.gif" 

img[200]="images/a_03.gif" 
img[201]="images/b_03.gif" 
img[202]="images/c_03.gif" 
img[203]="images/d_03.gif" 
img[204]="images/e_03.gif" 
img[205]="images/f_03.gif" 
img[206]="images/g_03.gif" 
img[207]="images/h_03.gif" 
img[208]="images/i_03.gif" 
img[209]="images/j_03.gif" 
img[210]="images/k_03.gif" 
img[211]="images/l_03.gif" 

img[300]="images/a_05.gif" 
img[301]="images/b_05.gif" 
img[302]="images/c_05.gif" 
img[303]="images/d_05.gif" 
img[304]="images/e_05.gif" 
img[305]="images/f_05.gif" 
img[306]="images/g_05.gif" 
img[307]="images/h_05.gif" 
img[308]="images/i_05.gif" 
img[309]="images/j_05.gif" 
img[310]="images/k_05.gif" 
img[311]="images/l_05.gif" 

img[400]="images/a_07.gif" 
img[401]="images/b_07.gif" 
img[402]="images/c_07.gif" 
img[403]="images/d_07.gif" 
img[404]="images/e_07.gif" 
img[405]="images/f_07.gif" 
img[406]="images/g_07.gif" 
img[407]="images/h_07.gif" 
img[408]="images/i_07.gif" 
img[409]="images/j_07.gif" 
img[410]="images/k_07.gif" 
img[411]="images/l_07.gif" 

img[500]="images/a_09.gif" 
img[501]="images/b_09.gif" 
img[502]="images/c_09.gif" 
img[503]="images/d_09.gif" 
img[504]="images/e_09.gif" 
img[505]="images/f_09.gif" 
img[506]="images/g_09.gif" 
img[507]="images/h_09.gif" 
img[508]="images/i_09.gif" 
img[509]="images/j_09.gif" 
img[510]="images/k_09.gif" 
img[511]="images/l_09.gif" 

img[600]="images/a_11.gif" 
img[601]="images/b_11.gif" 
img[602]="images/c_11.gif" 
img[603]="images/d_11.gif" 
img[604]="images/e_11.gif" 
img[605]="images/f_11.gif" 
img[606]="images/g_11.gif" 
img[607]="images/h_11.gif" 
img[608]="images/i_11.gif" 
img[609]="images/j_11.gif" 
img[610]="images/k_11.gif" 
img[611]="images/l_11.gif" 

function ChgImg(NumImg)
{
rand_no = Math.floor(12*Math.random());
i=eval(NumImg);
document.images[i].src=img[rand_no+(i+1)*100];
}