Help displaying Div's with menu

Hello, I am using this script to display and hide divs in my pages. You use a dropdown menu to select the div, which will then hide the other div(s). The issue I am having is that on loading the page both div's appear. How can I make it so that only one div shows by default. Here's the code I am using.

Here's a link to see it in action: http://www.plrfreedom.com/test.html

<script type="text/javascript">
function el(tid) { //gets an element by its ID.
return document.getElementById(tid);
}

//a show-hide toggle function
function showme(s) {
var elmt = el(s);
var els = elmt.style;
if (els.display && els.display != "none") {
elmt._sty_disp_bk = els.display ? els.display : "none";
elmt.style.display = "none";
} else {
elmt.style.display = elmt._sty_disp_bk || "block";
return 1;
}
}

function hide(s) {
el(s).style.display = "none";
}

function show(s) {
el(s).style.display = "block";
}
</script>
</head>


<select onchange="i=this.options[this.selectedIndex].text; if(i=='Version 1'){ show('block'); hide('block2'); };if(i=='Version 2'){ hide('block'); show('block2')}" style="width: 100px; font-size: xx-small;" name="coordinates">
<option value="">Select Version...
<option id="searchblock" value="">Version 1
<option id="searchblock2" value="">Version 2
</select>


<div id="block">
Another Tester
</div>

<div id="block2">
Just Testing
</div>

 

This should be bery simple for someone with some html or php experience.. Can someone solve this please.

Thanks