[Plugin: Theme My Login] Causing Javascript Error

When I have Theme My Login activated I get a d is null error unless I am on the actual login page. How do I get it to not call this function on every page?

<script type=”text/javascript”>
function wp_attempt_focus() {
setTimeout( function() {
try {
d = document.getElementById(‘user_login’);
d.value = ”; *********PROBLEM LINE *********
d.focus();
} catch(e){}
}, 200 );
}
wp_attempt_focus();
if(typeof wpOnload==’function’)wpOnload()
</script>