Passing a JavaScript variable to a html <select> attribute

I am trying to pass a variable from JavaScript to value attribute of the select tag. Here is my code:

<script>

 if (window.location.href.substring(0, 9) === "http://ww") {
     var home_var = "bing.com";
     var home_var = "poem.com";
 } else if (window.location.href.substring(0, 9) === "https://p") {
     var home_var = "https://px.multiscreensite.com/index.php?url=bing.com";
     var poem_var = "https://px.multiscreensite.com/index.php?url=poem.com";
 } else {
     var home_var = "1";
     var_poem_var = "2";
 }
 console.log(home_var);

</script>

<select OnChange="window.location.href=this.value">
   <option>Tagged Stuff and Navigation</option>
   <option value=HOME_VAR>Home Page</option>
</select>