javascript实现自动验证表单的代码分享

<script>
/**
* 自动验证表单
* edit by www.jb200.com
*/
(function(){
 if(window.addEventListener) window.addEventListener("load",init,false);
 else if(window.attachEvent) window.attachEvent("onload",inint);

 function init()
 {
  for (var i=0;i<document.forms.length ;i++ )//页面中所有表单
  {
   var f=document.forms[i];
             var needValidate = false;//是否需要验证
   for(var j=0;j<f.elements.length;j++)//表单中所有元素
   {
              var e=f.elements[j];
     if(e.type!="text") continue;

     var pattern=e.getAttribute("pattern");//获取正则
              var required=e.getAttribute("required")!=null;//是否是必须
   
     if(required && !pattern)
    {
      pattern='S';
      e.setAttribute("pattern",pattern);
    }
    else{
     e.onchange=validateOnChange;
     needValidate=true;
    }
        }
    }
  if(needValidate) f.onsubmit=validateOnSubmit;
  }
  function validateOnChange()
  {
    var textfield=this;
    var pattern=textfield.getAttribute("pattern");
    var value=this.value;

    if(value.search(pattern)== -1) textfield.className="invalid";
    else textfield.className="valid";
  }

  function validateOnSubmit()
     {
   var invalid=false;
   for(var i=0;i<this.elements.length;i++)
   {
    var e=this.elements[i];
    if(e.type="text" && e.onchange == validateOnChange)
    {
     e.onchange();
     if(e.className=="invalid") invalid=true;
    }
   }
   if(invalid){
    alert ("呵呵，有错误，请认真核对");
    return false;
   }
  }
})();
<script>

<!--引入js文件-->
<script language="javascript" src="validate.js"></script>
<!--form表单-->
<form>
name:<input type="text" name="name" required><br>
email:<input type="text" name="email" pattern="^s*w+@w+.w+s*$"><br>
<input type="submit" value="submit">
</form>