function isEmail(vEMail)  
{  
    var regInvalid=/(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.)/;  
    var regValid=/^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/;  
    return (!regInvalid.test(vEMail)&&regValid.test(vEMail));  
}  
function check()  
{  
 if  (!(isEmail(document.submitform.femail.value )))  
   {  
    alert("Please correct input your E-mail address!");  
    return false;  
    }  
 else  
 {  document.submitform.tHtml.value=document.submitform.innerHTML;   
  document.submitform.submit();}  

} 
// JavaScript Document