I want to be able to show iframe only when you click submit:

<script type="text/javascript">
function showIFrame() {
var iframe = document.getElementById("#myiframe");
iframe.style.display="block";
}
</script>

in my css file

#myiframe {
display:none; }

<form name="search" id="search" method="get" action="http://tmccaffery.outsideagents.com/travel/car/search.rvlx" target="carsearch">

<iframe id="#myiframe" name="carsearch" width="535" height="625" scrolling="no" frameborder="0"></iframe>


<button type="submit" id="SearchCarButton" class="submitBtn" onclick="showIFrame()"/> <span>Search</span></button>