PHP practice: a small forum (with backend)_PHP tutorial

<?php
//该函数用于处理注册的相关信息验证
require_once '../class/connectMysql.php';

//检查表单是否填写完整
function filled($form_var){
	foreach ($form_var as $key=>$value){
		if (!isset($key) || ($value=='')){
			return false;
		}
		return true;
	}
}

//验证邮箱是否有效
function verifyemail($email){
	if (@ereg('^[a-zA-Z0-9_\.\-]+@([a-zA-Z0-9][a-zA-Z0-9\-]*\.)+[a-zA-Z]+$', $email)){
		return true;
	}else {
		return false;
	}
}

//检查用户名是否已经存在
//$connectmysql为数据库连接对象
function verifyname($username,$connectmysql){
	$sql="select * from db_reglog where username='$username'";
	$res=$connectmysql->getRowsNum($sql);
	if ($res !=''){
		return true;
	}else {
		return false;
	}
	
}

//将注册信息写入数据库
//$connectmysql为数据库连接对象
function register($name,$passd,$email,$connectmysql){
	$sql="insert into db_reglog values('$name',sha1('$passd'),'$email','')";
	$res=$connectmysql->uidresult($sql);
	if ($res != ''){
		return true;
	}else {
		return false;
	}
	
}