var img = new Array();
 img[0] = new Image();  img[0].src = "image/tabtop.gif";
 img[1] = new Image();  img[1].src = "image/tabtop1.gif";
 img[2] = new Image();  img[2].src = "image/tabrepo.gif";
 img[3] = new Image();  img[3].src = "image/tabrepo1.gif";
 img[4] = new Image();  img[4].src = "image/tabmar.gif";
 img[5] = new Image();  img[5].src = "image/tabmar1.gif";
 img[6] = new Image();  img[6].src = "image/tabclim.gif";
 img[7] = new Image();  img[7].src = "image/tabclim1.gif";
 img[8] = new Image();  img[8].src = "image/tabtr.gif";
 img[9] = new Image();  img[9].src = "image/tabtr1.gif";
 img[10] = new Image();  img[10].src = "image/tabinfo.gif";
 img[11] = new Image();  img[11].src = "image/tabinfo1.gif";
 img[12] = new Image();  img[12].src = "image/tabres.gif";
 img[13] = new Image();  img[13].src = "image/tabres1.gif";
 img[14] = new Image();  img[14].src = "image/tabsup.gif";
 img[15] = new Image();  img[15].src = "image/tabsup1.gif";
 img[16] = new Image();  img[16].src = "image/sitesearch.gif";
 img[17] = new Image();  img[17].src = "image/sitesearch1.gif";

function change_image(nam,num) {
    document.images[nam].src = img[num].src; }