注册验证，提交等，大家怎么做？

function getlength(str)
{
return str.replace(/[^\x00-\xff]/g,"**").length;
function validate()
{
    if (getlength(document.regiform.TextBox1.value) <1)
{
alert("不能为空！");
document.regiform.TextBox1.focus();
return false;
}
  return true;
}
<head runat="server">
<script type="text/javascript" src="check.js"></script>
</head>
<body>
    <form id="regiform" runat="server" onsubmit="javascript:return validate();">
    <div id="text">
        <asp:TextBox ID="TextBox1" runat="server" Style="position: relative"></asp:TextBox>//这个判断为空
        <asp:TextBox ID="TextBox2" runat="server" Style="position: relative"></asp:TextBox>>//这个判断为email
    </div>

    <asp:button id="tijiao" runat="server" text="check" />

       </form>
这样<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" OnClientClick="return check()" />