求助ASP初级问题，弹出窗口文本框为什么不能输入字符？
运行下边程序为什么不能在文本框中输入字符？<%@LANGUAGE="VBSCRIPT" CODEPAGE="936"%>
<HTML>
<HEAD>
<TITLE>Popup Example</TITLE>
<SCRIPT>
var oPopup = window.createPopup();
function popmsg(){
var winstr="<form method=\"post\" name=\"test\"><table align=\"center\" border=\"1\" bgcolor=\"bbbbbb\">";
winstr=winstr+"<tr><td class=\"labels\"><label>用户名：</label></td><td ><input name=\"u1\" type=\"text\" ></td></tr>";
winstr=winstr+"<tr><td class=\"labels\"><label>密码：</label></td>";
winstr=winstr+"<td><input name=\"u2\" type=\"password\" ></td>";
winstr=winstr+"</tr><tr><td colspan=\"2\" align=\"center\"><input name=\"b1\" type=\"submit\" value=\"提交\">";
winstr=winstr+"</td></tr></table></form>";
var oPopBody = oPopup.document.body;
oPopBody.style.backgroundColor = "lightyellow";
oPopBody.style.border = "solid black 2px";
oPopup.document.body.innerHTML = winstr
oPopup.show(200, 50, 400, 500,document.body);
}
</SCRIPT>
</HEAD>
<BODY >
<BUTTON onClick="popmsg()">弹出对话框</BUTTON>
</BODY>
</HTML>
