javascript程序分析题。请填写划线部分 。。。怎么做求解

<script type="text/前梁卜javascript">

var ___=50

____ {

var formElements=document.getElementById("_____").elements

var userNameStr=fromElements[_____].value

var objSel=document.getElementsByTagName("_____")[0]

var subjectTypeStr=________.text

var memoStr=document.__getElementsByTagName_______("userMemo")[0].value

document.write("编慧穗号："+userNameStr+"<br>")

document.write("选择渣型的学科类别："+memoStr+"<br>")

document.write("输入的备注："+memoStr+"<br>")

document.write("<hr><div><a href='javascript:history.___back___()'>返回上一页</a></div>")

return false

}

function countChars() {

var __ jMemo____=document.getElementById("userMemoID")

var memoContent = ob jMemo.value..................

......

.......

memoContent= memoContent.substring(___________)

第一题：

function foo() {

for(var i=0i<form1.radioGroup.lengthi++){

if(form1.radioGroup[i].checked){

alert("第袜唤" + (i+1) + "个")

break

}

}

return false

}

第二题：

function reverse(str) {

temp = ""告备凯

for (var i = str.length-1i >滚握= 0i--)

{

temp = temp + str.charAt(i)

}

return temp

}

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