String.prototype.trim = function(){
  return  this.replace(/(^\s*)|(\s*$)/g, "");
};

Validator = {};

Validator.isImage = function(filename){
  if(filename){
    filename = filename.trim();
    var dotIndex = filename.lastIndexOf(".");
    var ext = filename.substr(dotIndex).toLowerCase();
    if(ext == ".gif" || ext == ".jpg" || ext == ".jpeg" || ext == ".png" || ext == ".bmp"){
      return true;
    }
    alert("文件名“" + filename + "”不是合法的图片文件，只能上传gif,jpg,png,bmp格式的图片文件。");
  }
  return false;
};

function $(id){return document.getElementById(id);}

function KeyDown(){
var keycode=event.keyCode;
if(keycode==13){event.keyCode=9;}
}

function toEnd(){
var e = event.srcElement;
var r =e.createTextRange();
r.moveStart('character',e.value.length);
r.collapse(true);
r.select();
}