function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		cmenu_home_over = newImage("images/cmenu_home-over.jpg");
		cmenu_about_over = newImage("images/cmenu_about-over.jpg");
		cmenu_product_over = newImage("images/cmenu_product-over.jpg");
		cmenu_service_over = newImage("images/cmenu_service-over.jpg");
		cmemu_support_over = newImage("images/cmemu_support-over.jpg");
		cmenu_contact_over = newImage("images/cmenu_contact-over.jpg");
		preloadFlag = true;
	}
}
////////////////  check email and submit ////////////////////////
function validate_email(field,alerttxt)
{
	with (field)
	{
	apos=value.indexOf("@")
	dotpos=value.lastIndexOf(".")
	if (apos<1||dotpos-apos<2) 
  		{alert(alerttxt);return false}
	else {
			if(document.pressed == 'subscribe') 
			{ 
			document.book_dm.action ="bookepaper_process.php"; 
			} 
			else 
			if(document.pressed == 'cancel') 
			{ 
			document.book_dm.action ="cancelepaper_process.php"; 
			} 
			return true; 
		}
	}
}
function validate_form(thisform)
{
	with (thisform)
	{
	if (validate_email(email,"invalid email\n please fill in again!!")==false)
  	{email.focus();email.style.backgroundColor='#faa';return false}
	}
}

////////////////////////////
//top瓜夹 
function respos(){ 
  dynamicbutton.style.pixelLeft=document.body.scrollLeft+300;
  dynamicbutton.style.pixelTop=document.body.scrollTop+500;
}


function checknull(){
 if(document.search_form.search_box1.value==''){
 alert('not null');
 document.search_form.search_box1.focus();
 document.search_form.search_box1.style.backgroundColor='#faa';
 return false
 }
}