我是javascript的新手，拿了一大堆代码并修改它供我自己使用。它在Firefox（* NIX和Windows）中运行良好。在IE8中，文本字段验证工作正常，但即使选择了选项，选择下拉菜单也会返回无效。
<!DOCTYPE html>
<head>
<meta charset="utf-8 />
<link href="/FNMOC/CSS/styles.main.css" rel="stylesheet" type="text/css">
<title>Fleet Numerical Meteorology and Oceanography Center</title>
<link rel="icon" href="favicon.ico">
<script type="text/javascript">
var RequiredFieldIDs =
'FirstName,LastName,Affiliation,Command,Email,Phone,METOC,Classification,Purpose,Priority,Due,NELat,SWLat,NELong,SWLong';
function CheckRequiredFields()
{
RequiredFieldIDs = RequiredFieldIDs.replace(/[, ]+/,",");
var idList = RequiredFieldIDs.split(",");
var Empties = new Array();
{
var s = TrimFormFieldValues(document.getElementbyId(idList[i]).value);
if (s.length<1) { Empties.push(idList[i]); }
}
if (! Empties.length) { return true; }
var ess = new String ("\n\nThe Following are required:\n");
for (var i=0; i<Empties.length; i++) { ess += '\n\t' + Empties[i]; }
alert (ess);
return false;
}
function TrimFormFieldValues(s)
{
s = s.replace (/^\s*/,"");
s = s.replace (/\s*$/,"");
}
</script>
<script type="text/javascript">
function ShowMenu()
{
var form = document.climo;
var field = form.Classification;
var select = field.selectedIndex;
{
if(select == 4) document.getElementById('tableHide').style.display = '';
else document.getElementById('tableHide').style.display = 'none';
}
}
</script>
<script type="text/javascript">
function ShowMenu2()
{
var form = document.climo;
var field = form.Affiliation;
var select = field.selectedIndex;
{
if(select == 1)document.getElementById('tableHide2').style.display = "";
else document.getElementById('tableHide2').style.display = 'none';
}
}
</script>
</head>
<body>
<div class="wrapper">
<div class="banner">
<iframe src="/FNMOC/banner.html" width="100%" height="30" frameBorder="0" scrolling="no">
</iframe>
</div>
<div class="classification">
<h2>THIS PAGE UNCLASSIFIED</h2>
</div>
<div class="header">
<a href="/FNMOC/index.html">
<img class="floatright" src="/FNMOC/IMAGES/fnmoc.png" />
</a>
<br />
<h3>
We produce and deliver weather, ocean and climate information for Fleet Safety, Warfighting Effectiveness and National Defense.
<br />
<br />
Atmospheric and Oceanographic Prediction enabling Fleet Safety and Decision Superiority
</h3>
<br />
<br />
</div>
<div class="left_col">
<iframe src="/FNMOC/menu.html" width="100%" height="800" frameBorder="0" scrolling="no">
</iframe>
</div>
<div class="main_col">
<center>
<h2>FORM UNCLASSIFIED UNTIL FILLED OUT</h2>
<h2>Climatology Support Request</h2>
</center>
<form name=climo action="/CGI/mail-form-climo.cgi" method="post" onsubmit="return CheckRequiredFields();">
<table border="0" cellpadding="5" width="100%">
<tr>
<td width="100%" colspan="2" align="center">
<hr>
<b>
<h2>
<center>
Contact Information
</h2>
</b>
<i>
* indicates required field
</i>
</center>
<hr>
</td>
</tr>
<tr>
<td width="30%">
<b>* First Name:</b>
</td>
<td width="70%">
<input type="text" id="FirstName" size="20" maxlength="250" name="1. First Name:">
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>* Last Name:</b>
</td>
<td width="70%">
<input type="text" id="LastName" size="30" maxlength="250" name="2. Last Name:">
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>* Affiliation:</b>
</td>
<td width="70%">
<select id="Affiliation" name="3. Affiliation:" onchange="!!(ShowMenu2());" size="1">
<option></option>
<option>MIL</option>
<option>CIV</option>
<option>CTR></option>
</select>
</td>
</tr>
<tr>
<td width="30%">
</td>
<td width="70%">
<table style="display:none" id="tableHide2">
<tr>
<td>
Branch of Service:
<select name="4. Branch of Service:" size="1">
<option></option>
<option>USN</option>
<option>USAF</option>
<option>USA</option>
<option>USMC</option>
<option>USCG</option>
</select>
</td>
</tr>
<tr>
<td>
Rank:
<input type="text" id="Rank" size="10" maxlength="10" name="5. Rank:">
</input>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td width="30%">
<b>
* Command/Organization:
</b>
</td>
<td width="70%">
<input="text" id="Command" size="30" maxlength="250" name="6. Command/Organization:">
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>* Email:</b>
</td>
<td width="70%">
<input type="text" id="Email" size="30" maxlength="250" name="7. Email:"
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>* Phone Number:</b>
</td>
<td width="70%">
<input type="text" id="Phone" size="30" maxlength="30" name="8. Phone number:">
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>DSN:</b>
</td>
<td width="70%">
<input type="text" size="13" maxlength="13" name="9. DSN:">
</input>
</td>
</tr>
<tr>
<td width="30%>
<b>* Are you meterologist or Oceanographer personnel?</b>
</td>
<td width="70%">
<select id="METOC" name="11. METOC:">
<option></option>
<option>YES</option>
<option>NO</option>
</select>
</td>
</tr>
<tr>
<tr width="100%" colspan="2" align="center">
<hr>
<b>
<h2>
Security Classification
</h2>
</b>
<center>
<i>
* indicates required field
</i>
</center>
<hr>
<i>
If classified, provide derivative and declassification info please.
</i>
<hr>
<br />
</td>
</tr>
<tr>
<td width="30%">
<b>* Classification of this request:</b>
</td>
<td width="70%">
<select id="Classification" name="12. Classification:" onchange="!!(ShowMenu()); size="1">
<option></option>
<option>UNCLASSIFIED</option>
<option>CONFIDENTIAL</option>
<option>SECRET</option>
<option>TOP SECRET</option>
</select>
</td>
</tr>
<tr>
<td width="30%">
</td>
<td width="70">
<table style="display:none" id="tableHide">
<tr>
<td>
<input type=checkbox name="12a. Caveat:" value="SI">SI</input>
<input type=checkbox name="12b. Caveat:" value="TK">TK</input>
<input type=checkbox name="12c. Caveat:" value="NOFORN">NOFORN</input>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td width="30%">
<b>Classified By:</b>
</td>
<td width="70%">
<input type="text" size="40" maxlength="250" name="13. Classified By:">
</input>
</td>
</tr>
<td width="100%" colspan="2" align="center">
<hr>
<b>
<h2>
Request Information
</h2>
</b>
<i>
* Indicates Required Field
</i>
<hr>
</td>
</tr>
<tr>
<td width="100%" colspan="2" align="center">
<b>
MISSION INFORMATION
</b>
<hr>
<br />
</td>
</tr>
<tr>
<td width="30%">
<b>* Mission Support Catagory:</b>
</td>
<td width="70%">
<select id=Purpose name="17. Purpose:" size="1">
<option></option>
<option>Combat/Operation</option>
<option>Contingency</option>
<option>Exercise</option>
<option>Training</option>
<option>Experiment</option>
<option>Research</option>
</select>
<b>Mission Name:</b>
<input type="text" size="20" maxlength="250" name="18. Purpose name:">
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>* Priority</b>
</td>
<td width="70%">
<select id="Priority" name="19. Priority:" size="1">
<option></option>
<option>LOW</option>
<option>MED</option>
<option>HIGH</option>
<option>URGENT</option>
</select>
</td>
</tr>
<tr>
<td width="30%">
<b>* Due date:</b>
</td>
<td width="70%">
<input type="text" size="10" maxlength="10" id="Due" name="20. Date due:">
</input>
</td>
</tr>
<tr>
<td width="30%">
<b>* Location</b>
<br />
provide NE/SW corner latitude and longitude in decimal format of each mesh you will use for applicataion/forcasting.
<br />
Northern hemisphere latitude is + and Southern hemisphere latitude is -, Eastern longitude from GMT is + and Western longitude from GMT is -.
</td>
<td width="70%">
<table>
<tr>
<td width="50%" aligh="right">
NE Latitude: <input type="text" id=NELat size="10" maxlength="250" name="22. NE Lat:">
</input>
<br />
SW Latitude: <input type="text" id=SWLat size="10" maxlength="250" name="23. SW Lat:">
</input>
</td>
<td width="50%" align="right">
NE Longitude:  <input type="text" id=NELong size="10" maxlength="250" name="24. NE Long:">
</input>
<br />
SW Longitude: <input type="text" id=SWLong size="10" maxlength="250" name="25. SW Long:">
</input>
</td>
</tr>
</table>
</td>
</tr>
</table>
<hr>
<center>
<input type="submit" name="Submit" value="Submit">
</input>
<input type="reset" name="Reset" value="Reset">
</input>
</center>
</form>
</div>
<br class="cleaner" />
<div class="classification">
<h2>THIS PAGE UNCLASSIFIED</h2>
</div>
<div class="banner">
<iframe src="/FNMOC/banner.html" width="100%" height="30" frameBorder="0" scrolling="no">
</iframe>
</div>
</div>
</body>
</html>
其他选择字段具有相同的代码，只是不同的名称/值。在IE8中没有选择验证。非常感谢你的帮助。
已修改为根据请求添加所有代码
答案 0 :(得分：0)
验证选择框的方式不正确。您可以获得所选选项的价值，例如select.value，它可以在Forefox和Chrome中使用。然而，正确的方法是让IE也能理解它，使用所选选项的值：
var el = document.getElementbyId(idList[i]);
var s = TrimFormFieldValues(el.options[el.selectedIndex].value);
如果表单中有不同类型的控件，则可以使用此检查检查当前控件是否为selectbox：
if (idList[i].tagName == 'SELECT') {
// this is select, get the value using el.options[el.selectedIndex].value
}