注册验证的实例

var warnusername="长度为4-20位，建议使用英文(a-z、A-Z)、数字(0-9)组合。";
var warnuserpwd="长度为6-20位，建议使用英文(a-z、A-Z)、数字(0-9)组合，注意区分英文大小写；密码不能与登录名相同。";
var warnconfirmuserpwd="确认密码要与密码完全一致，注意区分英文字母大小写。";
var warnemail="填写您的真实Email地址，这是今后您忘记密码，享受我们各项会员服务的必要途径。";
var warnquestion="如果您忘记了登录密码，可以通过您的密码提示问题/答案找回密码。";
var warnanswer="密码提示问题答案可以是任何字符，包括数字、字母、特殊字符、汉字等。";
function getfocus(objname)
{
 var obj=document.getElementById(objname)
 var divobj=document.getElementById("d_"+objname);
 switch(obj.id)
 {
  case "username":
   divobj.innerHTML=warnusername;
   divobj.className="WarningMsg";
   break;
  case "userpwd":
   divobj.innerHTML=warnuserpwd;
   divobj.className="WarningMsg";
   break;
  case "confirmuserpwd":
   divobj.innerHTML=warnconfirmuserpwd;
   divobj.className="WarningMsg";
   break;
  case "email":
   divobj.innerHTML=warnemail;
   divobj.className="WarningMsg";
   break;
  case "question":
   divobj.innerHTML=warnquestion;
   divobj.className="WarningMsg";
   break;
  case "answer":
   divobj.innerHTML=warnanswer;
   divobj.className="WarningMsg";
   break;
 }
}
function lostfocus(objname)
{
 var obj=document.getElementById(objname)
 var divobj=document.getElementById("d_"+objname);
 switch(obj.id)
 {
  case "username":
   var len=trim(obj.value).length
   if(len==0 || len<4 || len>20)
   {
    divobj.innerHTML=warnusername;
    divobj.className="ErrorMsg";
   }
   else
   {
    //检查用户名是否合法
    divobj.innerHTML="正在检测中...";
       document.getElementById("checkfrm").src="checkuserpwd.aspx?username="+obj.value+""
   }
   break;
  case "userpwd":
      var len=trim(obj.value).length
      if(len==0 || len<6 || len>20 ||(obj.value==document.getElementById("username").value))
   {
    divobj.innerHTML=warnuserpwd;
    divobj.className="ErrorMsg";
   }
   else
   {
    divobj.innerHTML="密码填写正确";
    divobj.className="OkMsg";
   }
      break;
  case "confirmuserpwd":
   if((obj.value!=document.getElementById("userpwd").value) || obj.value.length==0)
   {
       divobj.innerHTML=warnconfirmuserpwd;
    divobj.className="ErrorMsg";
   }
   else
   {
       divobj.innerHTML="密码验证正确";
    divobj.className="OkMsg";
   }
   break;
     case "email":
            if(!CheckEmail(obj.value))
            {
                divobj.innerHTML=warnemail;
    divobj.className="ErrorMsg";
            }
            else
            {
                divobj.innerHTML="";
    divobj.className="OkMsg";
            }
   break;
  case "question":
      if(trim(obj.value).length==0)
      {
          divobj.innerHTML=warnquestion;
    divobj.className="ErrorMsg";
      }
      else
       {
          divobj.innerHTML="";
    divobj.className="OkMsg";
        }
      break;
  case "answer":
      if(trim(obj.value).length==0)
      {
       divobj.innerHTML=warnanswer;
       divobj.className="ErrorMsg";
   }
   else
   {
       divobj.innerHTML="";
    divobj.className="OkMsg";
   }
   break;
 }
}
function init()
{
 var obj=document.getElementsByTagName("div")
 for(var i=0;i<obj.length;i++)
 {
  switch(obj[i].id)
  {
   case "d_username":
    obj[i].innerHTML=warnusername;
    break;
   case "d_userpwd":
       obj[i].innerHTML=warnuserpwd;
    break;
   case "d_confirmuserpwd":
       obj[i].innerHTML=warnconfirmuserpwd;
       break;
   case "d_email":
       obj[i].innerHTML=warnemail;
       break;
   case "d_question":
       obj[i].innerHTML=warnquestion;
       break;
   case "d_answer":
       obj[i].innerHTML=warnanswer;
       break;
   
  }
 }
}
init();
function checkfrm()
{
    if(!document.getElementById("CheckBox1").checked)
    {
        alert('如果您阅读了协议,请勾选复选框！')
        return false
    }
    if(document.getElementById("code").value.length==0)
    {
        alert("请输入验证码")
        return false
    }
    return true
}
function ResetImage()
{
    document.getElementById('imgcode').src="/members/images.aspx?"+Math.random()+""
}