JavaScript简单实现鼠标拖动选择功能

代码如下:
<style><!--
body{padding-top:50px;padding-left:100px;padding-right:150px;}
  .fileDiv{float:left;width:100px;height:100px;text-align:center;line-height:100px;font-size:12px;border:1px solid #cccccc;margin-right:10px;margin-bottom:10px;}
  .seled{border:1px solid #ff0000;background-color:#D6DFF7;}
--></style>
<script type="text/javascript">// <![CDATA[
Array.prototype.remove = function( item ){
  for( var i = 0 ; i < this.length ; i++ ){
   if( item == this[i] )
    break;
  }
  if( i == this.length )
   return;
  for( var j = i ; j < this.length - 1 ; j++ ){
   this[ j ] = this[ j + 1 ];
  }
  this.length--;
  }

String.prototype.replaceAll = function (AFindText,ARepText){ raRegExp = new RegExp(AFindText,"g"); return this.replace(raRegExp,ARepText);}
 function getAllChildren(e) {
  return e.all ? e.all : e.getElementsByTagName('*');
}

document.getElementsBySelector = function(selector) {
  if (!document.getElementsByTagName) {
    return new Array();
  }
  var tokens = selector.split(' ');
  var currentContext = new Array(document);
  for (var i = 0; i < tokens.length; i++) {
    token = tokens[i].replace(/^/s+/,'').replace(//s+$/,'');;
    if (token.indexOf('#') > -1) {
      var bits = token.split('#');
      var tagName = bits[0];
      var id = bits[1];
      var element = document.getElementById(id);
      if (tagName  &&  element.nodeName.toLowerCase() != tagName) {
        return new Array();
      }
      currentContext = new Array(element);
      continue;
    }
    if (token.indexOf('.') > -1) {

      var bits = token.split('.');
      var tagName = bits[0];
      var className = bits[1];
      if (!tagName) {
        tagName = '*';
      }

      var found = new Array;
      var foundCount = 0;
      for (var h = 0; h < currentContext.length; h++) {
        var elements;
        if (tagName == '*') {
            elements = getAllChildren(currentContext[h]);
        } else {
            elements = currentContext[h].getElementsByTagName(tagName);