javascript验证邮箱有效性函数

function isEmail(strEmail) {
  if (strEmail.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1){
   return true;
}else{
   alert("Email格式不正确！");
   document.formSignUp.email.value="";
   document.formSignUp.email.focus();
 }
}