function validemail(addr) {   // sub function to validate correctness of e-mail address entry.

    var poa = addr.indexOf("@",1);
    var ivc = " /:,;"
    
    if (addr == "") {alert("Please enter your e-mail address."); return false}
    
    for(i=0; i<ivc.length; i++) { 
       badch = ivc.charAt(i);
       if (addr.indexOf(badch) > -1) {
        alert("Invalid character in e-mail address.\n\(cannot be a space or / or : or , or ;\) ");
        return false;
       } 
    }
    
    if (poa == -1 || addr.indexOf("@", poa+1) != -1) {
        alert("Email address must contain an @ but only one @.");
        return false;
       } 
      
    if (addr.indexOf(".", poa+1) == -1) {
        alert("Email address must contain at least one  .  after the @.");
        return false;
       } 
    
  return true
 }



 function validphone(phone) {   // sub function to validate telephone number entry.

        var digts = 0;
    
   if (phone == "") {alert("Please enter your telephone number\n including area code."); return false}

    
    for(i=0; i<phone.length; i++) { 
        
      var num = parseInt(phone.charAt(i));
      
     for(j=0; j<10; j++) { 
      
      if (num == j) digts++;

     } 
    
    }
    
   if(digts < 10) {alert("Please enter your telephone number\n including area code."); return false}
        
   else return true;
 }