// JavaScript Document
function chk_email(){
	
	if(emailform.emailaddress.value == "" || emailform.emailaddress.value.indexOf == -1){
	   		alert("Please fill in your email address.\n請填寫你的電郵地址.");
	   
	   }else if(emailform.emailaddress.value == "" || emailform.emailaddress.value.indexOf('@',0) == -1 || emailform.emailaddress.value.indexOf('.',0) == -1){
			alert("Please fill in correct email address.\n請填寫正確的電郵地址.");
	   
	   }else{
			return true;   
	   }
	return false;
}

function buttonok(){
	
	surveyform.button.disabled = false;
}