这个正则表达式这样加上位数限制？

Question

if ( reg.email.value.length<8 || reg.email.value.length>50)
{
     alert("长度不对");
     reg.email.focus();
     return false;
}

Answer 1

试试:if(!(/^([A-Za-z0-9][\w\-]*[A-Za-z0-9])\@[A-Za-z0-9][A-Za-z0-9-]*[A-Za-z0-9](\.[A-Za-z0-9]+){8,50}$/).test(reg.email.value)){alert("Email不合法");reg.email.focus();return(false);}

Answer 2

if(/^[\w\@\.]{8,50}$/.test(reg.email.value))
  {
    if(!(/^([A-Za-z0-9][\w\-]*[A-Za-z0-9])\@[A-Za-z0-9][A-Za-z0-9-]*[A-Za-z0-9](\.[A-Za-z0-9]+)+$/).test(reg.email.value)){alert("Email不合法");reg.email.focus();return(false);}  }
else
  {
    return false;
  }