我点击按钮时怎么不执行login()函数

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>你可以拖动我吗？</title>
<script language="javascript">
<!--
function cry(){
alert("你可以拖动我吗？")
}
//-->
</script><script language="javascript">
<!--
window.alert = function(txt)
{
var shield = document.createElement("DIV");
shield.id = "shield";
shield.style.position = "absolute";
shield.style.left = "0px";
shield.style.top = "0px";
shield.style.width = "100%";
shield.style.height = "100%";
//shield.style.height = document.body.scrollHeight+"px";
shield.style.background = "#ccc";
shield.style.textAlign = "center";
shield.style.zIndex = "10000";
shield.style.filter = "alpha(opacity=0)";
var alertFram = document.createElement("DIV");
alertFram.id="alertFram";
alertFram.style.position = "absolute";
//负边界居中法,相对于shield层的顶部时//alertFram.style.left = "50%";
//alertFram.style.top = "50%";
//alertFram.style.marginLeft = "-125px";
//alertFram.style.marginTop = "-75px";//负边界居中法,相对于shield层的底部时
alertFram.style.right = "30%";
alertFram.style.bottom = "50%";
alertFram.style.marginRight = "-125px";
alertFram.style.marginBottom = "-75px";alertFram.style.width = "250px";
alertFram.style.height = "150px";
alertFram.style.background = "#000";
alertFram.style.textAlign = "center";
alertFram.style.lineHeight = "150px";
alertFram.style.zIndex = "10002";
strHtml = "<ul style=\"list-style:none;margin:0px;padding:0px;width:100%\">\n";
strHtml += "<li onmousedown=\"oMove(parentNode.parentNode);\" title=\"移動\" style=\"cursor:move;background:#002F9C;text-align:left;padding-left:5px;font-size:14px;font-weight:bold;color: #FFFFFF;height:25px;line-height:25px;border-left:1px solid #FFFFFF;border-top:1px solid #FFFFFF;border-right:1px solid #FFFFFF;\">[提示……]</li>\n";
strHtml += "<li style=\"background:#5A7EDC;text-align:center;font-size:12px;color: #FFFFFF;height:120px;line-height:120px;border-left:1px solid #FFFFFF;border-right:1px solid #FFFFFF;\">"+txt+"</li>\n";
strHtml += "<li style=\"background:#002F9C;text-align:center;font-weight:bold;height:25px;line-height:25px; border-left:1px solid #FFFFFF;border-bottom:1px solid #FFFFFF;border-right:1px solid #FFFFFF;\"><input type=button value=' 确定 ' onclick=\"remove()\"></li>\n";
strHtml += "</ul>\n";
alertFram.innerHTML = strHtml;
document.body.appendChild(alertFram);
document.body.appendChild(shield);var c = 50;
this.doAlpha = function(){
if (c++ > 75){clearInterval(ad);return 0;}
shield.style.filter = "alpha(opacity="+c+");";
}
  this.remove=function(){
   alertFram.innerHTML="";
    shield.style.filter = "";
    shield.id = "";
    shield.style.position = "";
    shield.style.left = "";
    shield.style.top = "";
    shield.style.width = "";
    shield.style.height ="";
    shield.style.background = "";
    shield.style.textAlign = "";
    shield.style.zIndex = "";
    shield.style.filter = "";
    alertFram.id="";
    alertFram.style.position = "";
    alertFram.style.left = "";
    alertFram.style.top = "";
    alertFram.style.marginLeft = "";
    alertFram.style.marginTop = "";
    alertFram.style.width = "";
    alertFram.style.height = "";
    alertFram.style.background = "";
    alertFram.style.textAlign = "";
    alertFram.style.lineHeight = "";
    alertFram.style.zIndex = "";
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  {
    obj.onmousemove = null;
    obj.style.filter = null;
    obj.releaseCapture();
  }
}//-->
</script>
<script language="javascript">
function login(){
if(document.myform.loginId.value==""){
alert("请输入E-mail!")
document.myform.loginId.focus()
return false
}
if(document.myform.loginPwd.value==""){
alert("请输入密码!")
document.myform.loginPwd.focus()
return false
}
document.myform.action="login.action?Source=welcom";
document.myform.submit();

}
function register(){
document.myform.action="register.action";
document.myform.submit();
}function errorok()
{
document.getElementById("log_error").style.display = "none"
document.getElementById("log_error_mask").style.display = "none"
}
</script>
</head><body style="margin:0;">
<input type=submit name="cry" value="点击我一下下^_^" style="width: 110px; height: 30px" onclick='return cry();'></input>
 <form action="" method="post" name="myform" id="myform">
          <label>E-mail:</label>
          <div class="log_inp">
            <input type="text" class="log_inp_txt" id="loginId" name="loginId" value=""/>
          </div>
          <div class="clea10"></div>
          <label>密&nbsp;&nbsp;&nbsp;码:</label>
          <div class="log_inp">
            <input type="password" class="log_inp_txt" id="loginPwd" name="loginPwd"/>
          </div>
          <div class="clea10"></div>
          <div class="log_inp"> <span class="red">*</span>忘记密码的用户，请点击<a class="red ud_line" href="">这里</a> </div>
          <div class="clea10"></div>
          <div class="log_inp">
            <input type="button" name="button" value="" class="button01" onclick="login()"/>
            &nbsp;
            <input type="button" value="" class="button07"  onclick="document.location='index.action'" />
          </div>
          <div class="clea10"></div>
        </form>
</body></html>问题，我点击按钮时怎么不执行login()函数呢？