输入表单内容判断过滤,JavaScript

<div id="research">
<form name="sumitForm" method="post" action="http://search.chinanews.com/search.do" target="_blank" onSubmit="return submitFun()">
<img src="/200711/2008817164835.gif" width="43" height="20" style="vertical-align:middle;" />
<input type="text" name="keyword" id="keyword" autocomplete="off" class="12-1v" maxlength="10" size="22" value="关键字" onFocus="this.value=''" style="width:100px;"/>
<select name="filed" id="filed">
<option value="title" selected>标题</option>
<option value="content">内容</option>
</select>
<input type=image src="/200711/2008817164823.gif" width="23" height="23" name="submit2" />
<input type="hidden" name="pageIndex" id="pageIndex" value="1" />
<input type="hidden" name="isEncode" id="isEncode" value="false" />
<input type="hidden" name="day1" id="day1" />
<input type="hidden" name="day2" id="day2" />
<input type="hidden" name="ad_is" id="ad_is" value="false" />
</form>
</div>
<script type="text/javascript">
String.prototype.trim= function() {
    return this.replace(/(^\s*)|(\s*$)/g, "");
}
// Example: obj = findObj("image1");
function findObj(theObj, theDoc) {
var p, i, foundObj;
if(!theDoc) theDoc = document;
if( (p = theObj.indexOf("?")) > 0 && parent.frames.length) {
   theDoc = parent.frames[theObj.substring(p+1)].document;
   theObj = theObj.substring(0,p);
}
if(!(foundObj = theDoc[theObj]) && theDoc.all) foundObj = theDoc.all[theObj];
for (i=0; !foundObj && i < theDoc.forms.length; i++)
   foundObj = theDoc.forms[i][theObj];
for(i=0; !foundObj && theDoc.layers && i < theDoc.layers.length; i++)
   foundObj = findObj(theObj,theDoc.layers[i].document);
if(!foundObj && document.getElementById) foundObj = document.getElementById(theObj);
return foundObj;
}
/**
* 判断输入变量是否是特殊字符
* 特殊字符：_ - * & % $ # @ ! ~ ^ ( )等
* @param {String} 要检查的变量值
* @return {Array} 是否特殊字符,该特殊字符
*/
function isSpecialChar(w) {
var isSpecialChar = RegExp(/^[(\\)(\<)(\>)(\.)(\,)(\;)(\")(\')(\:)(\、)(\？)(\：)(\”)(\“)(\‘)(\’)(\。)(\，)(\》)(\《)(\；)(\！)(\（)(\）)(\…)(\—)(\{)(\})(\|)(\[)(\])(\/)(\=)(\+)(\_)(\-)(\*)(\&)(\%)(\$)(\#)(\@)(\!)(\~)(\^)($)($)]+$/);
var len = w.length;
var ch;
var b = false;
var rsArr = new Array();
for (var i=0; i<len; i++) {
  ch = w.charAt(i);
  if (isSpecialChar.test(ch)) {
   b = true;
   rsArr[1] = ch;
  }
}
rsArr[0] = b;
return rsArr;
}
/**
* 判断输入变量是否是特殊单词
* 特殊单词 "and","or","like","is" 等
* @param {String} 要检查的变量值
* @return {Array} 是否特殊单词,该特殊单词
*/
function isSpecialWord(w) {
//alert(w);
var specialWordArr = new Array("and","or","like","is");
var b = false;
var sw = "";
var rsArr = new Array();
for (var i=0; i< specialWordArr.length; i++) {
  if (w.indexOf(specialWordArr[i]) != -1) {
   b = true;
   sw = specialWordArr[i];
   break;
  }
}
rsArr[0] = b;
rsArr[1] = sw;
return rsArr;
}
//查询表单提交函数
function submitFun() {
var keyword = findObj("keyword").value;
var formObj = findObj("sumitForm");
var ad_is = findObj("ad_is").checked;
var day1Obj = findObj("day1");
var day2Obj = findObj("day2");
if (keyword.trim() == "") {
  alert("请输入关键字然后提交进行查询！");
  return false;
} else if(isSpecialChar(keyword)[0] == true){
  alert("您的输入包含一个非法字符\""+ isSpecialChar(keyword)[1] +"\"，请尝试重新输入！");
  return false;
} else if (isSpecialWord(keyword)[0] == true) {
  alert("您的输入包含一个非法单词\""+ isSpecialWord(keyword)[1] +"\"，请尝试重新输入！");
  return false;
}
}
</script>