Hjælp til validering af javascrip kode

Min kode viker under IE, men ikke i firefox, er der nogle som kan se om der er IE kode i mit script her som bør rettes?

<SELECT name="country" onchange="window.frames['jsiframe'].location.href = '/logic/iframe.php?val=' + escape(this.options[this.selectedIndex].value);">

<script language="javascript">
    document.form.country.focus();
</script>

<SELECT name="country" onchange="jsiframe.location = '/logic/iframe.php?val='+this[this.selectedIndex].value;">


<SELECT NAME="choice" onchange="location = '<?php $PHP_SELF?>?attach=show&menuid=6&choice='+this[this.selectedIndex].value;">

<a href="?attach=show&menuid=6" class="submit" onclick="document.wheretobuy.submit()" class="submit">Display retailers</a>

<iframe name="jsiframe" src="/logic/iframe.php?val=0" id="IFRAMEID" style="height:0px;width:0px;border:0px;"></iframe>