请教HTML文本框内输入正确的邮件格式的写法，回复立即给分

请问HTML文本框内输入正确的邮件格式的写法，回复立即给分
<input   name= "mail "     type= "text "         /> 如何添加？谢谢

[解决办法]
<script language= "JavaScript ">

function check(){

var msg= " ";

if (document.info.telephone.value.length < 6) {

msg+= "您输入的电话有误！\n\n ";

}

var email_length=document.info.email.value.length;

var tab1=document.info.email.value.indexOf( "@ ");

var domain=document.info.email.value.substring(tab1+1,email_length);



if(tab1==-1 || tab1==0 || domain.indexOf( "@ ")!=-1 || domain.indexOf( ". ")==-1 || (domain.indexOf( ". ")+tab1+2)==email_length || email_length < 5) {

msg+= "您输入的电子信箱有误！\n\n ";

}