function changecss(theme_slug){
	var css_url = "/theme/"+theme_slug+"/style.css";
	if(theme_slug != ""){
		clear_user_css();
		$('#skin').attr( 'href',css_url ) ;
		$('#theme_slug').val(theme_slug);
		$('#no_bg').attr( 'checked','checked' ) ;
	}
}

function clear_user_css(){
	$("#user_css").html('');
}

function chk_clear(objId,bg_img,position){
	var objId,bg_img,position;
	if(document.getElementById(objId).checked){
		clear_user_css();
	}else{
		restore_user_css(bg_img,position);
	}
}

function restore_user_css(bg_img,position){
	var bg_img,position;
	$("#user_css").html('html,body{background:url('+bg_img+') '+position+' top;background-attachment: fixed;}');
}