isamap = new Object();
isamap[0] = "_df"
isamap[1] = "_ov"
isamap[2] = "_ot"
isamap[3] = "_dn"

function isimgact(id, act)
{
	if(document.images) document.images[id].src = eval( "isimages." + id + isamap[act] + ".src");
}

if (document.images) { // ensure browser can do JavaScript rollovers.
isimages = new Object();
isimages.sidebar1_df = new Image();
isimages.sidebar1_df.src = "images/Houstan_04.gif";

isimages.sidebar1_ov = new Image();
isimages.sidebar1_ov.src = "images/Houstan_04_roll.gif";

isimages.sidebar2_df = new Image();
isimages.sidebar2_df.src = "images/Houstan_05.gif";

isimages.sidebar2_ov = new Image();
isimages.sidebar2_ov.src = "images/Houstan_05_roll.gif";

isimages.sidebar3_df = new Image();
isimages.sidebar3_df.src = "images/Houstan_06.gif";

isimages.sidebar3_ov = new Image();
isimages.sidebar3_ov.src = "images/Houstan_06_roll.gif";

isimages.sidebar4_df = new Image();
isimages.sidebar4_df.src = "images/Houstan_07.gif";

isimages.sidebar4_ov = new Image();
isimages.sidebar4_ov.src = "images/Houstan_07_roll.gif";

isimages.sidebar5_df = new Image();
isimages.sidebar5_df.src = "images/Houstan_08.gif";

isimages.sidebar5_ov = new Image();
isimages.sidebar5_ov.src = "images/Houstan_08_roll.gif";

isimages.sidebar6_df = new Image();
isimages.sidebar6_df.src = "images/Houstan_16.gif";

isimages.sidebar6_ov = new Image();
isimages.sidebar6_ov.src = "images/Houstan_16_roll.gif";

isimages.sidebar7_df = new Image();
isimages.sidebar7_df.src = "images/Houstan_17.gif";

isimages.sidebar7_ov = new Image();
isimages.sidebar7_ov.src = "images/Houstan_17_roll.gif";

isimages.sidebar8_df = new Image();
isimages.sidebar8_df.src = "images/Houstan_18.gif";

isimages.sidebar8_ov = new Image();
isimages.sidebar8_ov.src = "images/Houstan_18_roll.gif";

isimages.sidebar9_df = new Image();
isimages.sidebar9_df.src = "images/Houstan_21.gif";

isimages.sidebar9_ov = new Image();
isimages.sidebar9_ov.src = "images/Houstan_21_roll.gif";

isimages.sidebar10_df = new Image();
isimages.sidebar10_df.src = "images/Houstan_22.gif";

isimages.sidebar10_ov = new Image();
isimages.sidebar10_ov.src = "images/Houstan_22_roll.gif";

isimages.sidebar11_df = new Image();
isimages.sidebar11_df.src = "images/Houstan_24.gif";

isimages.sidebar11_ov = new Image();
isimages.sidebar11_ov.src = "images/Houstan_24_roll.gif";
}