function emailCheck(emailStr) {


var emailPat=/^(.+)@(.+)$/;
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
var validChars="\[^\\s" + specialChars + "\]";
var quotedUser="(\"[^\"]*\")";
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
var atom=validChars + '+';
var word="(" + atom + "|" + quotedUser + ")";
var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
var matchArray=emailStr.match(emailPat);
if (matchArray==null) {
return false;
}
var user=matchArray[1];
var domain=matchArray[2];

if (user.match(userPat)==null) {
    return false;
}

var IPArray=domain.match(ipDomainPat);
if (IPArray!=null) {
    for (var i=1;i<=4;i++) {
      if (IPArray[i]>255) {
    return false;
      }
    }
    return true;
}

var domainArray=domain.match(domainPat)
if (domainArray==null) {
    return false;
}

var atomPat=new RegExp(atom,"g");
var domArr=domain.match(atomPat);
var len=domArr.length;
if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>3) {
   return false;
}

if (len<2) {
   var errStr="This address is missing a hostname!";
   return false;
}
return true;
}

function checkData() {
warn = "";
df = document.send_to_friend_form;

if (df.fullname.value == "") {
  warn += "Please enter your Name.\n";
    }
if (df.email.value == "") {
  warn += "Please enter your Email address.\n";
    }
else {
  if (!emailCheck(df.email.value)) {
    warn += "Please make sure Email address is in proper format. (\'username@domain.ext\' or \'username@\[IP Address\]\')\n";
    }
  if (df.email.value == "username@domain.ext") {
    warn += "Please use your valid Email address.\n";
    }
  }
if (df.interest.selectedIndex == 0) {
  warn += "Please select an Area of Interest from the menu.\n";
  }
if (df.country.selectedIndex == 0) {
  warn += "Please select your Country from the menu.\n";

  }
  
if (warn == "") {
  return true;
  }
else {
  alert('* * * PLEASE MAKE THE FOLLOWING CORRECTIONS * * *\n_______________________________________________\n\n' + warn);
  return false;
  }
}



function check_stf_Data() {
warn = "";
df = document.send_to_friend_form;

if (df.your_name.value == "") {
  warn += "Please enter your Name.\n";
    }
if (df.friends_name.value == "") {
  warn += "Please enter your friend's Name.\n";
    }
if (df.your_email.value == "") {
  warn += "Please enter your Email address.\n";
    }
else {
  if (!emailCheck(df.your_email.value)) {
    warn += "Please make sure your Email address is in proper format. (\'username@domain.ext\' or \'username@\[IP Address\]\')\n";
    }
  if (df.your_email.value == "username@domain.ext") {
    warn += "Please use your valid Email address.\n";
    }
  }
if (df.friends_email.value == "") {
  warn += "Please enter your friend's Email address.\n";
    }
else {
  if (!emailCheck(df.friends_email.value)) {
    warn += "Please make sure your friend's Email address is in proper format. (\'username@domain.ext\' or \'username@\[IP Address\]\')\n";
    }
  if (df.friends_email.value == "username@domain.ext") {
    warn += "Please use your friend's valid Email address.\n";
    }
  }

  
if (warn == "") {
  return true;
  }
else {
  alert('* * * PLEASE MAKE THE FOLLOWING CORRECTIONS * * *\n_______________________________________________\n\n' + warn);
  return false;
  }
}