/**

 * @date 2014/04/18

 *  wzj

 * guestbook data check

 * 

**/

function checkForm()

{

var gosubmit = true;

    //email check

    var email = document.getElementById("email");

    if(email.value != '')

    {

     if(!(/^([a-zA-Z0-9]+[_|\_|\.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|\_|\.]?)*[a-zA-Z0-9]+\.[a-zA-Z]{2,3}$/).test(email.value))

      {

      alert('请输入有效的邮箱地址!');

      email.focus();             

      gosubmit = false;

      }

    }

    //telephone check

    var tel = document.getElementById("tel");

    if(!(/^1[3|4|5|8][0-9]\d{4,8}$/).test(tel.value))

    {

     alert('请输入有效的手机号!');

     tel.focus();             

     gosubmit = false;

    }

    //qq check

    var qq = document.getElementById("qq");

    if(qq.value != '')

    {

     if(!(/^\d[1-9]{5,10}$/).test(qq.value))

     {

      alert('请输入有效的QQ号!');

      qq.focus();             

      gosubmit = false;

     }

    }

    

   return gosubmit;

}

<form action = "#" onsubmit = "return checkForm" method="post">

<input id = "email" type="text" />

<input id = "tel" type="text" />

<input id = "qq" type="text" />

</form>