function validateEmailForm(form){
  if (0>=form.t.value.indexOf('@') || form.t.value.indexOf('@')+1>=form.t.value.length) {
   alert ('Please enter a valid To Email Address');
   form.t.focus();
   return false;
  }
  else {
   ch = vef_checkChars(form.t.value, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789@.-_");
   if (ch!=null) {
    alert("To Email Address cannot contain the character '" + ch + "'");
    form.t.focus();
    return false;
   }
  }

  if (0>=form.f.value.indexOf('@') || form.f.value.indexOf('@')+1>=form.f.value.length) {
   alert ('Please enter a valid Your Email Address');
   form.f.focus();
   return false;
  }
  else {
   ch = vef_checkChars(form.f.value, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789@.-_");
   if (ch!=null) {
    alert("Your Email Address cannot contain the character '" + ch + "'");
    form.f.focus();
    return false;
   }
  }

  if(form.s.value=="" || form.s.value==null) {
   alert("Please enter a Subject");
   form.s.focus();
   return false;
  }

  if(form.b.value=="" || form.b.value==null) {
   alert("Please enter a Comment");
   form.b.focus();
   return false;
  }

  return true;
 }

 function vef_checkChars(text, allowedChars, preMessage, postMessage) {
   for (i=0; i<text.length; i++) {
    if (allowedChars.indexOf(text.charAt(i))==-1) {
     if (text.charAt(i)==' ') return '<space>';
     else return text.charAt(i);
    }
   }
   return null;
 }