javascript代码不运行

<html>
  <head>
    
<script language="JavaScript" type="text/javascript">
function clears(object,value){
        
if(object.value==value)object.value="";
}
function resume(object,value){
if(object.value=="")object.value=value;
}
function rand(){
var code="";
var array=new Array{"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t"
,"u","v","w","x","y","z"};
for(var i=0;i<4;i++){
var index=Math.floor(Math.random()*26);
code+=array[index];
}
document.getElementById("verifycode").innerHTML=code;
}
function login(){
if(form1.name.value==""){
alert("请输入用户名！");
return false;
}
if(form1.password.value==""){
alert("请输入密码！");
return false;
}
if(form1.checkcode.value==""){
alert("请输入验证码！");
return false;
}
if(form1.checkcode.value!=document.getElementById("verifycode").innerHTML){
alert("输入的验证码不正确！");
rand();
return false;
}
form1.submit();
}
</script>
  </head>
  
  <body onload="rand();">
    <h1 align="center"><span style="color: red;">welcome you</span></h1>
    <hr>
    <h3 align="center">${errorMessage}</h3>
    <form name="form1" action="luserlogin.action" method="post">
    <table align="center" cellpadding="5" cellspacing="20">
     <tr>
     <td align="center" valign="middle"><span style="color: red;">用户名:</span></td>
     <td align="left" valign="middle"><input name="name" type="text" size="30" maxlength="16"
     value="请输入用户名"
     onfocus="clears(this,'请输入用户名');" onblur="resume(this,'请输入用户名');"></td>
     </tr>
     <tr>
     <td align="center" valign="middle"><span style="color: red;">密码：</span></td>
     <td align="left" valign="middle"><input name="password" type="text" size="30" maxlength="16"></td>
     </tr>
     <tr>
     <td align="center" valign="middle"><span style="color: red;">验证码：</span></td>
     <td align="left" valign="middle"><input name="checkcode" type="text" size="15" maxlength="4">&nbsp;&nbsp;
     <label id="verifycode" style="background-color: gray;">8888</label></td>
     </tr>
     <tr>
     <td align="center" valign="middle" colspan="2"><input type="button" value="登录" onclick="login();">
     &nbsp;&nbsp;&nbsp;&nbsp;<input type="reset" value="重置"></td>
     </tr>
    
    </table>
    </form>
  </body>
</html>