If you are trying to remove the message box that appears when you hit your back button when using the OE catalog, drop this javascript in your master template page (default.wc) just about the </body> tag.
A
<script type="text/javascript">
if (typeof SophioAjaxCatalog === "undefined") {
SophioAjaxCatalog = {};
}
SophioAjaxCatalog.preventPageLeave=false;
</script>