The below line opens a selected index from a drop down in a browser window. The form field is in a div called "contents". I need to know the syntax needed to open this selection in another div on the same page called "main". The "_top" location opens the file in a new window. I want to open this on the same page. Do I need javascript for this?
onchange="[this.selectedIndex].value,'_top')" style="text-align: center">
Here is all the code for my file:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "">
<html xmlns="">

<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<title>Untitled 1</title>
<style type="text/css">
.banner {
	background-color: #000000;
	width: 100%;
	height: 25px;
.contents {
	width: 180px;
	height: 560px;
	background-color: #0000FF;
.main {
	width: 100%;
	height: 100%;
	background-color: #006600;

<div id="banner" class="banner">
<div id="contents" class="contents">
<form action="../">
&nbsp;&nbsp; <br />
<select onchange="[this.selectedIndex].value,'_blank')" style="text-align: center">
    <option value="">Choose a destination...</option>
    <option value="">CLIMATE</option>
    <option value="">2011</option>
    <option value="">ALTAVISTA</option>
    <option value="">AMAZON</option>
    <option value="">ARTLUNG</option>
<div id="main" class="main" style="position: absolute; width: 1148px; height: 564px; z-index: 1; top: 43px; left: 192px">