请教高人帮我看看为什么报脚本错误?

<%@ page contentType="text/html; charset=GBK" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GBK">
<title>文件上传</title>
<style type="text/css">
<!--
form {
font-size: 9pt;
}
body {
font-size: 9pt;
}
table {
font-size: 9pt;
}-->
</style></head>
<body bgcolor="#718BD6" leftmargin="0" topmargin="0">
<%
String method=request.getMethod();
if(method.equals("POST"))
{
String deptNo=null;
String yearNo=null;
String docNo=null;
deptNo = request.getParameter("deptno");
yearNo = request.getParameter("yearno");
docNo = request.getParameter("docno");
%>
<script  language="JavaScript">
var result=new Array();
result[0]="<%=deptNo%>";
result[1]="<%=yearNo%>";
result[2]="<%=docNo%>";
parent.closeUpload(result);
</script>
<%
}
%>    
<script language="JavaScript">
function fileCheck()
{
    var deptno = document.forms[0].deptno.value;
    var yearno = document.forms[0].yearno.value;
    var docno = document.forms[0].docno.value;
    if(deptno.length == 0) {
        alert("发文部门不能为空");
        return false;
    }
    else if ((yearno.match(/\d\d\d\d/)) == null || yearno.length!=4 || yearno.length!=(yearno.match(/\d\d\d\d/))[0].length) {
            alert("年号输入不合法,请输入4位年份!");
            return false;
    }   else if ((docno.match(/[0-9]{1,}/))==null || docno.length!=(docno.match(/[0-9]{1,}/))[0].length){
            alert("红头文号输入不正确,请输入数字!");
            return false;
    }
    form1.submit();//就是这句,我去掉就不报脚本错误,不去掉就报错说对象不支持此属性或方法
}
</script>      
<form action="" method="POST" name="form1" id="form1">
    <table>
        <tr>
            <td>发布部门</td>
            <td><input name="deptno" id="deptno" type="text" size="25"></td>
            </tr>
            <tr>
                <td>年号</td>
                <td><input name="yearno" id="yearno" type="text" size="25">只能输入年份</td>
                </tr>
                <tr>
                    <td>红头文号</td>
                    <td><input name="docno" id="docno" type="text" size="25">只能输入数字</td>
                    </tr>
                    <tr>
                        <td><input type="button" name="submit" value="确定" onclick="fileCheck()"/></td>
                        <td><input type="reset"  name="reset" value="重置"/></td>
                    </tr>
                </table>
            </form>
</body>
</html>-----------------------------------------浏览器提示我下面这句有错
form1.submit();
就是这句,我去掉就不报脚本错误,不去掉就报错说对象不支持此属性或方法求高手解答,如果不这样写我要如何写来提交表单啊?谢谢!