var imgMax  = 8; //セットする画像の枚数。
var imgRand = Math.floor(Math.random() * imgMax);

if(imgRand == 0)       document.write('<IMG src="ctr_img/ctr_rdm/ctr_etc/bss_pht_0000.gif" width=300 height=400 border=0>');

else if(imgRand == 1)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/byz_pht_0735.jpg" width=300 height=400 border=0>');

else if(imgRand == 2)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/byz_pht_2279.jpg" width=300 height=400 border=0>');

else if(imgRand == 3)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/gso_pht_0724.jpg" width=300 height=400 border=0>');

else if(imgRand == 4)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/gso_pht_1794.jpg" width=300 height=400 border=0>');

else if(imgRand == 5)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/byz_pht_2209.jpg" width=300 height=400 border=0>');

else if(imgRand == 6)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/vyn_pht_1395.jpg" width=300 height=400 border=0>');

else if(imgRand == 7)  document.write('<IMG src="ctr_img/ctr_rdm/ctr_llg_203/vyn_pht_1002.jpg" width=300 height=400 border=0>');