document.execCommand('SaveAs')设置问题?

document.execCommand('SaveAs')
弹出框里的保存类型可以设置成只有xls吗?
弹出框里的语言选择默认显示是Unicode,可以设置成打开是简体中文(GB2312)吗?
以下是网页表格中用脚本导出EXCEL代码，不知要加什么才能实现保存类型默认是EXCEL
<SCRIPT LANGUAGE="javascript">function method1(tableid) {//整个表格拷贝到EXCEL中    var curTbl = document.getElementById(tableid);    var oXL = new ActiveXObject("Excel.Application");    //创建AX对象excel    var oWB = oXL.Workbooks.Add();    //获取workbook对象    var oSheet = oWB.ActiveSheet;    //激活当前sheet    var sel = document.body.createTextRange();    sel.moveToElementText(curTbl);    //把表格中的内容移到TextRange中    sel.select();    //全选TextRange中内容    sel.execCommand("Copy");    //复制TextRange中内容     oSheet.Paste();    //粘贴到活动的EXCEL中          oXL.Visible = true;    //设置excel可见属性}function method2(tableid) //读取表格中每个单元到EXCEL中{    var curTbl = document.getElementById(tableid);    var oXL = new ActiveXObject("Excel.Application");    //创建AX对象excel    var oWB = oXL.Workbooks.Add();    //获取workbook对象    var oSheet = oWB.ActiveSheet;    //激活当前sheet    var Lenr = curTbl.rows.length;    //取得表格行数    for (i = 0; i < Lenr; i++)    {        var Lenc = curTbl.rows(i).cells.length;        //取得每行的列数        for (j = 0; j < Lenc; j++)        {            oSheet.Cells(i + 1, j + 1).value = curTbl.rows(i).cells(j).innerText;            //赋值        }    }    oXL.Visible = true;    //设置excel可见属性}function getXlsFromTbl(inTblId, inWindow) {    try {        var allStr = "";        var curStr = "";         //alert("getXlsFromTbl");        if (inTblId != null && inTblId != "" && inTblId != "null") {            curStr = getTblData(inTblId, inWindow);        }         if (curStr != null) {            allStr += curStr;        }        else {            alert("你要导出的表不存在！");            return;        }         var fileName = getExcelFileName();        doFileExport(fileName, allStr);     }    catch(e) {        alert("导出发生异常:" + e.name + "->" + e.description + "!");    }}function getTblData(inTbl, inWindow) {    var rows = 0;     //alert("getTblData is " + inWindow);    var tblDocument = document;     if (!!inWindow && inWindow != "") {        if (!document.all(inWindow)) {            return null;        }        else {            tblDocument = eval(inWindow).document;        }    }     var curTbl = tblDocument.getElementById(inTbl);     var outStr = "";     if (curTbl != null) {        for (var j = 0; j < curTbl.rows.length; j++) {            //alert("j is " + j);            for (var i = 0; i < curTbl.rows[j].cells.length; i++) {                //alert("i is " + i);                if (i == 0 && rows > 0) {                    outStr += " \t";                    rows -= 1;                }                outStr += curTbl.rows[j].cells[i].innerText + "\t";                if (curTbl.rows[j].cells[i].colSpan > 1) {                    for (var k = 0; k < curTbl.rows[j].cells[i].colSpan - 1; k++) {                        outStr += " \t";                    }                }                if (i == 0) {                    if (rows == 0 && curTbl.rows[j].cells[i].rowSpan > 1) {                        rows = curTbl.rows[j].cells[i].rowSpan - 1;                    }                }            }            outStr += "\r\n";        }    }    else {        outStr = null;        alert(inTbl + "不存在!");    }    return outStr;}function getExcelFileName() {    var d = new Date();     var curYear = d.getYear();    var curMonth = "" + (d.getMonth() + 1);    var curDate = "" + d.getDate();    var curHour = "" + d.getHours();    var curMinute = "" + d.getMinutes();    var curSecond = "" + d.getSeconds();     if (curMonth.length == 1) {        curMonth = "0" + curMonth;    }    if (curDate.length == 1) {        curDate = "0" + curDate;    }    if (curHour.length == 1) {        curHour = "0" + curHour;    }    if (curMinute.length == 1) {        curMinute = "0" + curMinute;    }    if (curSecond.length == 1) {        curSecond = "0" + curSecond;    }     var fileName = "leo_zhang" + "_" + curYear + curMonth + curDate + "_"            + curHour + curMinute + curSecond + ".csv";    //alert(fileName);

ContentType  =  "application/msexcel"    
    return fileName;} function doFileExport(inName, inStr) {    var xlsWin = null;     if (!!document.all("glbHideFrm")) {        xlsWin = glbHideFrm;    }    else {        var width = 6;        var height = 4;        var openPara = "left=" + (window.screen.width / 2 - width / 2)                + ",top=" + (window.screen.height / 2 - height / 2)                + ",scrollbars=no,width=" + width + ",height=" + height;        xlsWin = window.open("","_blank", openPara);    }     xlsWin.document.write(inStr);    xlsWin.document.close();    xlsWin.document.execCommand('Saveas', false, inName);
    xlsWin.close();}</SCRIPT>