var picArray = new Array('images/banner_discovercenter_proce.jpg','images/banner_discovercenter_lex.jpg','images/banner_discovercenter_map.jpg')

function ShowImage(picCode) {
document.getElementById('preview_img').src = picArray[picCode];
}
function HideImage() {
document.getElementById('preview_img').src = "images/content_dc_main.jpg";
}