function comment_trim(stringToTrim) {
	return stringToTrim.replace(/^\s+|\s+$/g,"");
}
function comment_check_submit(comment_string,email,yourname){
	
	var comment_string = document.getElementById(comment_string);
	var email = document.getElementById(email);
	var yourname = document.getElementById(yourname);
	
	var email_regexp = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9])+$/;
	
	if( (yourname.value.replace(/(\s*)/g, "")) == '' ){
		alert('請填寫姓名');
		return false;
	}
	if( (comment_string.value.replace(/(\s*)/g, "")) == '' ){
		alert('請留下你的留言');
		return false;
	}
	if( (email.value.replace(/(\s*)/g, "")) == '' ){
		alert('請填寫電郵');
		return false;
	}
	if( !email_regexp.test(email.value) ){
		alert('請正確填寫電郵');
		return false;
	}
	comment_string.value=comment_trim(comment_string.value);
	if((comment_string.value.length) > 500 )
	{
		alert('留言字數請少於500字');
		return false;
	}
	if((comment_string.value.length) < 3 )
	{
		alert('留言字數請大於2字');
		return false;
	}
	return true;
	
}
function comment_check_submit_login(comment_string){
	
	var comment_string = document.getElementById(comment_string);
	
	if( (comment_string.value.replace(/(\s*)/g, "")) == '' ){
		alert('請留下你的留言');
		return false;
	}
	comment_string.value=comment_trim(comment_string.value);
	if((comment_string.value.length) > 500 )
	{
		alert('留言字數請少於500字');
		return false;
	}
	if((comment_string.value.length) < 3 )
	{
		alert('留言字數請大於2字');
		return false;
	}
	return true;
	
}