我有这个登录表单:
<div id="loginform">
<div>
<img id="loginLogo" runat="server" />
</div>
<div class="row">
<label>Email</label>
<input name="UserNameBox" type="text" id="tbEmail" style="outline-style:none;"
tabindex="1" runat="server" onkeydown="if (event.keyCode == 13) validateExample()"
/>
</div>
<div class="row">
<label>Password</label>
<input name="PasswordBox" type="password" id="tbPassword"
tabindex="2" style="outline-style:none" runat="server" onkeydown="if (event.keyCode == 13) validateExample()"
/>
</div>
<div id="validationError" class="validationError" runat="server"></div>
<div style="margin-top: 15px; margin-left: 15px;" tabindex="3">
<input type="checkbox" id="cbRememberMe" name="rememberMe" runat="server"
tabindex="4" />remember me</div>
<center>
<input type="button" class="rounded-corners" onclick="validateExample()"
value="Login" tabindex="5" />
</center>
</div>
在我的设备中,用户名文本框的第一个字母的默认大小写为大写。我如何默认将其设为小写,但如果用户名以大写字母开头,用户仍然可以将其设为大写。