form.submit()不能提交表单的错误原因及解决方法

<div id="register"><h4>会员注册</h4><div class="formdiv"><form method="post" action="register.php?action=register" name="register" id="registerForm"><dl><dt>请认真填写以下内容</dt><dd class="hasspan">用户名：<input type="text" name="username"></dd><dd class="hasspan">密码：<input type="password" name="pwd"></dd><dd class="hasspan">确认密码：<input type="password" name="pwdagain"></dd><dd id="tximg"><img src="img/face/m01.gif" alt="选择头像" id="faceimg"><input type="hidden" name="touxiang" value=""><label id="imgsrclabel">m01.gif</label></dd><dd style="margin-right:120px;">验证码：<input type="text" name="code"><span><img src="code.php" alt="code" id="code" name="code"><a href="#code" id="change">换一张</a></span></dd><dd class="btns"><input type="button" name="submit" id="submit" value="注册"><input type="button" name="quit" id="quit" value="退出"></dd></dl></form></div></div>表单数据提交到本页面，下面是js处理/*注册表单提交*/function formDeal(){var btnSubmit = document.getElementById('submit');var formId = document.getElementById('registerForm');btnSubmit.onclick = function(){//表单的submit()方法不能提交表单formId.submit();}}如果表单提交，在本页面有一段提示信息if(!empty($_GET['action']) && $_GET['action'] == 'register'){echo '你提交了数据';exit();}